US 20070212405A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2007/0212405 A1 Dellamary et al. (43) Pub. Date: Sep. 13, 2007

(54) DISPERSION FOR PULMONARY DELIVERY of application No. 09/133,848, filed on Aug. 14, 1998, OF ABOACTIVE AGENT now abandoned, which is a continuation-in-part of application No. 09/106,932, filed on Jun. 29, 1998, (75) Inventors: Luis A. Dellamary, San Marcos, CA now abandoned. (US); Thomas E. Tarara, San Diego, CA (US); Alexey Kabalnov, Corvallis, (60) Provisional application No. 60/060,337, filed on Sep. OR (US); Jeffry G. Weers, San Diego, 29, 1997. CA (US); Ernest G. Schutt, San Diego, CA (US) Publication Classification Correspondence Address: (51) Int. Cl. NEKTAR THERAPEUTICS A6IR 9/16 (2006.01) 150 INDUSTRIAL ROAD A 6LX 9/27 (2006.01) SAN CARLOS, CA 94070 (US) (52) U.S. Cl...... 424/450: 424/490 (73) Assignee: Nektar Therapeutics (57) ABSTRACT Stabilized dispersions are provided for the delivery of a (21) Appl. No.: 11/675,073 bioactive agent. The dispersions preferably comprise a plu Filed: Feb. 14, 2007 rality of perforated microstructures dispersed in a Suspen (22) sion medium that typically comprises a liquid fluorochemi Related U.S. Application Data cal. As density variations between the Suspended particles and Suspension medium are minimized and attractive forces (63) Continuation of application No. 09/999,071, filed on between microstructures are attenuated, the disclosed dis Dec. 3, 2001, now Pat. No. 7,205,343, which is a persions are particularly resistant to degradation, such as by continuation of application No. 09/218.209, filed on settling or flocculation. In particularly preferred embodi Dec. 22, 1998, now Pat. No. 6,433,040, which is a ments the stabilized dispersions may be directly adminis continuation of application No. PCT/US98/20613, tered to the lung of a patient using an endotracheal tube or filed on Sep. 29, 1998, which is a continuation-in-part bronchoscope.

Patent Application Publication Sep. 13, 2007 Sheet 1 of 4 US 2007/0212405 A1

r = 0 Fl G A. 2

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C Cf C as 2.2 F G 1 C-2 Patent Application Publication Sep. 13, 2007 Sheet 2 of 4 US 2007/0212405 A1

ro Patent Application Publication Sep. 13, 2007 Sheet 3 of 4 US 2007/0212405 A1

Patent Application Publication Sep. 13, 2007 Sheet 4 of 4 US 2007/0212405 A1

US 2007/0212405 A1 Sep. 13, 2007

DISPERSION FOR PULMONARY DELIVERY OF A ness for certain forms of radiation and low surface energies, BOACTIVE AGENT have made fluorochemicals invaluable for a number of therapeutic and diagnostic applications. CROSS REFERENCE 0005 Among these applications is liquid ventilation. For 0001. The present application is a continuation of U.S. all practical purposes, liquid ventilation became a viable application Ser. No. 09/999,071 filed Dec. 3, 2001, which is technique when it was discovered that fluorochemicals could a continuation of U.S. Pat. No. 6,433,040 filed Dec. 22, be used as the respiratory promoter. Liquid breathing using 1998, which is a continuation of PCT Publication No. WO oxygenated fluorochemicals has been explored for some 99/16421 filed Sep. 29, 1998, which is a continuation-in-part time. For example, an animal Submerged in an oxygenated of U.S. patent application Ser. No. 09/133,848 filed Aug. 14, fluorochemical liquid, may exchange oxygen and carbon 1998, now abandoned, which is a continuation-in-part of dioxide normally when the lungs fill with the fluorochemi U.S. patent application Ser. No. 09/106,932 filed Jun. 29, cal. In this regard it has been shown that mammals can 1998, now abandoned, which claims priority from U.S. derive adequate oxygen for Survival when Submerged by Provisional Application Ser. No. 60/060,337 filed Sep. 29, breathing the oxygenated fluorochemical liquid. In particu 1997 and now lapsed. All of these applications are now lar, it has been established that total liquid ventilation may incorporated by reference herein in their entireties. keep mammals alive for extended periods prior to returning them to conventional gas breathing. BACKGROUND 0006 Those skilled in the art will appreciate that con 0002 Embodiments of the present invention relate to temporary liquid ventilation is an alternative to standard compositions, systems, and methods, for the pulmonary mechanical ventilation which involves introducing an oxy delivery to a patient, of microstructures in a suspension genatable liquid medium into the pulmonary air passages for medium. the purposes of waste gas exchange and oxygenation. Essen tially, there are two separate techniques for performing 0003. The efficacy of many pharmaceutical agents is liquid ventilation, total liquid ventilation and partial liquid predicated on their ability to proceed to the selected target ventilation. Total liquid ventilation or “TLV is the pulmo sites and remain there in effective concentrations for suffi nary introduction of warmed, extracorporeally oxygenated cient periods of time to accomplish the desired therapeutic liquid respiratory promoter (typically fluorochemicals) at a or diagnostic purpose. Difficulty in achieving efficacy may volume greater than the functional residual capacity of the be exacerbated by the location and environment of the target Subject. The Subject is then connected to a liquid breathing site as well as by the inherent physical characteristics of the system and tidal liquid volumes are delivered at a frequency compound administered. For example, drug delivery via depending on respiratory requirements while exhaled liquid routes that are subject to repeated drainage or flushing as is purged of CO and oxygenated extracorporeally between part of the body's natural physiological functions offer the breaths. This often involves the use of specialized fluid significant impediments to the effective administration of handling equipment. pharmaceutical agents. In this respect, delivery and retention problems are often encountered when administering com 0007 Conversely, partial liquid ventilation or “PLV” pounds through the respiratory or gastrointestinal tracts. involves the use of conventional mechanical ventilation in Repeated administration of fairly large doses are often combination with pulmonary administration of a respiratory required to compensate for the amount of drug washed away promoter capable of oxygenation. In PLV a liquid, vaporous and to maintain an effective dosing regimen when employ or gaseous respiratory promoter (i.e. a fluorochemical) is ing such routes. Moreover, the molecular properties of the introduced into the pulmonary air passages at Volumes pharmaceutical compound may impair the absorption ranging from just enough to interact with or coat a portion through a given delivery route, thereby resulting in a Sub of the pulmonary surface all the way up to the functional stantial reduction in efficacy. For instance, insoluble particu residual capacity of the Subject. Respiratory gas exchange lates are known to be subject to phagocytosis and pinocy may then be maintained for the duration of the procedure by, tosis, resulting in the accelerated removal of the compound for example, continuous positive pressure ventilation using from the target site. Such reductions in delivery and reten a conventional open-circuit gas ventilator, Alternatively, gas tion time complicate dosing regimes, waste pharmaceutical exchange may be maintained through spontaneous respira resources and generally reduce the overall efficacy of the tion. When the procedure is over, the introduced respiratory administered drug. promoter or fluorochemical may be allowed to evaporate from the lung rather than being physically removed as in 0004. In this respect, one class of delivery vehicles that TLV. For the purposes of the instant application the term has shown great promise when used for the administration of “liquid ventilation' will be used in a generic sense and shall pharmaceutical agents is fluorochemicals. During recent be defined as the introduction of any amount of respiratory years, fluorochemicals have found wide ranging application promoter or fluorochemical into the lung, including the in the medical field as therapeutic and diagnostic agents. The techniques of partial liquid ventilation, total liquid ventila use of fluorochemicals to treat medical conditions is based, to a large extent, on the unique physical and chemical tion and liquid dose installation. properties of these Substances. In particular, the relatively 0008 Use of liquid ventilation may provide significant low reactivity of fluorochemicals allows them to be com medical benefits that are not available through the use of bined with a wide variety of compounds without altering the conventional mechanical ventilators employing a breathable properties of the incorporated agent. This relative inactivity, gas. For example, the weight of the respiratory promoter when coupled with other beneficial characteristics such as an opens alveoli with much lower ventilator pressure than is ability to carry Substantial amounts of oxygen, radioopaque possible with gas. Additionally, liquid ventilation using US 2007/0212405 A1 Sep. 13, 2007

fluorochemicals as the respiratory promoter has been shown Such as flocculation, fusion, molecular diffusion, and coa to be effective in rinsing out congestive materials associated lescence. Over a relatively short period of time these pro with respiratory distress syndrome. Moreover, liquid venti cesses can coarsen the formulation to the point where it is no lation has been shown to be a promising therapy for the longer usable. As such, while Such systems are certainly a treatment of respiratory distress syndromes involving Sur Substantial improvement over prior art non-fluorochemical factant deficiency or dysfunction. Elevated alveolar surface delivery vehicles, the drug Suspensions may be improved tension plays a central role in the pathophysiology of the upon to enable formulations with improved stability that Respiratory Distress Syndrome (RDS) in premature infants also offer more efficient and accurate dosing at the desired and is thought to contribute to the dysfunction in children site. and adults. Liquid ventilation, particularly using fluoro chemicals, is effective in surfactant-deficient disorders DRAWINGS because it eliminates the air/fluid interfaces in the lung and thereby greatly reduces pulmonary Surface tension. More 0011 FIGS. 1A1 to 1F2 illustrate changes in particle over, liquid ventilation can be accomplished without undue morphology as a function of variation in the ratio of fluo alveolar pressures or impairing cardiac output and provides rocarbon blowing agent to phospholipid (PFC/PC) present excellent gas exchange even in premature infants. Finally, in the spray dry feed. The micrographs, produced using fluorochemicals have also been shown to have pulmonary scanning electron microscopy and transmission electron and systemic anti-inflammatory effects. microscopy techniques, show that the absence of FCs, or at 0009. In addition to liquid ventilation, it has been recog low PFC/PC ratios, the resulting spray dried microstructures nized that fluorochemicals may be effective in the pulmo comprising gentamicin Sulfate are neither particularly hol nary delivery of bioactive agents in the form of liquid or low or porous. Conversely, at high PFC/PC ratios, the solid particulates. For example, pulmonary delivery of bio particles contain numerous pores and are Substantially hol active agents using fluorochemical Suspensions is described low with thin walls. in Sekins et al., U.S. Pat. No. 5,562,608, Fuhrman, U.S. Pat. 0012 FIG. 2 is a scanning electron microscopy image of No. 5,437,272, Faithful et al. U.S. Pat. No. 5,490,498, perforated microstructures comprising cromolyn Sodium Trevino et al. U.S. Pat. No. 5,667,809 and Schutt U.S. Pat. illustrating a preferred hollow/porous morphology. No. 5,540.225 each of which is incorporated herein by reference. The bioactive agents may preferably be delivered 0013 FIGS. 3A to 3D are photographs illustrating the in conjunction with partial liquid ventilation or lavage. Due enhanced stability provided by the dispersions of the present to the physical characteristics of compatible respiratory invention over time as compared to a commercial cromolyn promoters or fluorochemicals, the use of Such techniques sodium formulation (Intal, Rhone-Poulenc-Rorer). In the provides for improved dispersion of the incorporated agent photographs, the commercial formulation on the left rapidly in the lung thereby increasing uptake and increasing efficacy. separates while the dispersion on the right, formed in Further, direct administration of the bioactive agent is par accordance with the teachings herein, remains stable over an ticularly effective in the treatment of lung disease as poor extended period. vascular circulation of diseased portions of the lung reduces the efficacy of intravenous drug delivery. Besides treating DESCRIPTION pulmonary disorders, fluorochemical pharmaceutical formu lations administered to the lung could also prove useful in 0014 While the present invention may be embodied in the treatment and/or diagnosis of disorders such as RDS, many different forms, disclosed herein are specific illustra impaired pulmonary circulation, cystic fibrosis and lung tive embodiments thereof that exemplify the principles of cancer. It will also be appreciated that, in addition to the the invention. It should be emphasized that the present pulmonary route of administration, fluorochemicals could invention is not limited to the specific embodiments illus advantageously be used for the administration of compounds trated. via other routes Such as topical, oral (e.g. for administration 0015. As set forth above, the present invention provides to the gastrointestinal tract), intraperitoneal, or ocular. methods and compositions that allow for the formation of Unfortunately, regardless of the administration route, the use stabilized Suspensions that may advantageously be used for of fluorochemical Suspensions may result in unreliable and the delivery of bioactive agents. The enhanced stability of irreproducible drug delivery due to the administration of a the Suspensions is primarily achieved by lowering the van non-homogeneous dispersion or instability of the particu der Waals attractive forces between the suspended particles, lates in the fluorochemical phase. and by reducing the differences in density between the 0010 More particularly, drug suspensions in liquid fluo Suspension medium and the particles. In accordance with the rochemicals comprise heterogeneous systems which usually teachings herein, the increases in Suspension stability may require redispersion prior to use. Yet, because of factors such be imparted by engineering perforated microstructures that as patient compliance, obtaining a relatively homogeneous are then dispersed in a compatible Suspension medium. In distribution of the pharmaceutical compound is not always this regard, the perforated microstructures comprise pores, easy or Successful. In addition, prior art formulations com voids, and hollows, defects or other interstitial spaces that prising micronized particulates may be prone to aggregation allow the fluid suspension medium to freely permeate or of the particles which can result in inadequate delivery of the perfuse the particulate boundary. Particularly preferred drug. Crystal growth of the Suspensions via Ostwald ripen embodiments comprise perforated microstructures that are ing may also lead to particle size heterogeneity and can hollow and porous, almost honeycombed or foam-like in significantly reduce the shelf-life of the formulation. appearance. In especially preferred embodiments the perfo Another problem with conventional dispersions is particle rated microstructures comprise hollow, porous spray dried coarsening. Coarsening may occur via several mechanisms microspheres. US 2007/0212405 A1 Sep. 13, 2007

0016. With respect to the instant specification, the terms can be visualized as attractions between fluctuating dipoles “perforated microstructures” and “perforated micropar (i.e. induced dipole-induced dipole interactions). Dispersion ticles' are used to describe porous products, preferably forces are extremely short-range and scale as the sixth power comprising a bioactive agent, distributed throughout the of the distance between atoms. When two macroscopic Suspension medium in accordance with the teachings herein. bodies approach one another the dispersion attractions Accordingly, the Subject terms may be used interchangeably between the atoms sums up. The resulting force is of throughout the instant specification unless the contextual considerably longer range, and depends on the geometry of setting indicates otherwise. the interacting bodies. 0017 When the perforated microstructures are placed in 0021 More specifically, for two spherical particles, the the Suspension medium (i.e. propellant), the Suspension magnitude of the VDW potential, VA, can be approximated medium is able to permeate the particles, thereby creating a by the equation: “homodispersion, wherein both the continuous and dis persed phases are substantially indistinguishable. Since the defined or “virtual particles (i.e. comprising the volume where A is the effective Hamaker constant which accounts circumscribed by the microparticulate matrix) are made up for the nature of the particles and the medium, Ho is the almost entirely of the medium in which they are suspended, distance between particles, and R and R2 are the radii of the forces driving particle aggregation (flocculation) are spherical particles 1 and 2. The effective Hamaker constant minimized. Additionally, having the microstructures filled is proportional to the difference in the polarizabilities of the with the medium, thereby effectively slowing particle dispersed particles and the Suspension medium: A = creaming or sedimentation minimizes the differences in (VAsm-VApART), where Asm and Apart are the Hamaker density between the defined particles and the continuous constants for the Suspension medium and the particles, phase. respectively. As the Suspended particles and the dispersion 0018. It should further be appreciated that the suspension medium become similar in nature. As and APART become medium may be any liquid or compound that is in liquid closer in magnitude, and A and VA become Smaller. That form, under appropriate thermodynamic conditions, for for is, by reducing the differences between the Hamaker con mation of a compatible particulate dispersion. Unless oth stant associated with Suspension medium and the Hamaker erwise dictated by contextual restraints, the terms "suspen constant associated with the dispersed particles, the effective sion medium, 'Suspension media” and “nonaqueous Hamaker constant (and corresponding van der Waals attrac continuous phase' are held to be equivalent for the purposes tive forces) may be reduced. of the instant application and may be used interchangeably. For embodiments wherein the stabilized dispersion is to be 0022. One way to minimize the differences in the used in conjunction liquid dose instillation, the Suspension Hamaker constants is to create a "homodispersion', that is medium preferably comprises hydrocarbons or fluorocar make both the continuous and dispersed phases essentially indistinguishable as discussed above. Besides exploiting the bons having a vapor pressure less than about one atmo morphology of the particles to reduce the effective Hamaker sphere. That is, it will preferably be a liquid under standard constant, the components of the structural matrix (defining conditions of one atmosphere and 25° C. the perforated microstructures) will preferably be chosen so 0019. Due to their stability and substantially homoge as to exhibit a Hamaker constant relatively close to that of neous nature, the stabilized suspensions of the present the selected Suspension medium. In this respect, one may invention are compatible with inhalation therapies and may use the actual values of the Hamaker constants of the be used in conjunction with metered dose inhalers, dry Suspension medium and the particulate components to deter powder inhalers and nebulizers. In particularly preferred mine the compatibility of the dispersion ingredients and embodiments the disclosed perforated microstructures may provide a good indication as to the stability of the prepara be dispersed in a suitable Suspension medium (e.g. a long tion. Alternatively, one could select relatively compatible chain liquid fluorochemical) and directly administered to the perforated microstructure components and Suspension medi pulmonary air passages of a patient in need thereof. For the ums using characteristic physical values that coincide with purposes of the instant specification, methods comprising measurable Hamaker constants but are more readily discern direct administration of a stabilized dispersion to the lungs ible. Such as through an endotracheal tube or a bronchoscope; will be termed liquid dose, instillation. While the composi 0023. In this respect, it has been found that the refractive tions of the present invention are particularly effective for index values of many compounds tend to scale with the pulmonary drug delivery, it will be appreciated that they corresponding Hamaker constant. Accordingly, easily mea may also be used to drugs to a variety of physiological sites Surable refractive index values may be used to provide a including body cavities and organs. Accordingly, the stabi fairly good indication as to which combination of Suspen lized dispersions may be administered topically, Subcutane sion medium and particle excipients will provide dispersion ously intramuscularly, intraperitoneally, nasally, vaginally, having a relatively low effective Hamaker constant and rectally, orally or ocularly. associated stability. It will be appreciated that, since refrac tive indices of compounds are widely available or easily 0020. In contrast to many prior art suspensions, the derived, the use of such values allows for the formation of dispersions of the present invention are designed not to stabilized dispersions in accordance with the present inven increase repulsion between particles, but rather to decrease tion without undue experimentation. For the purpose of attractive forces. The principal forces driving flocculation in illustration only, the refractive indices of several compounds nonaqueous, media are van der Waals (VDW) attractive compatible with the disclosed dispersions are provided in forces. VDW forces are quantum mechanical in origin, and Table I immediately below: US 2007/0212405 A1 Sep. 13, 2007

“particle volume” corresponds to the volume of suspension TABLE I medium that would be displaced by the incorporated hollow/ porous particles if they were solid, i.e. the volume defined by Compound Refractive Index the particle boundary. For the purposes of explanation these HFA-134a 1172 fluid filled particulate volumes may be referred to as “virtual HFA-227 1.223 particles.” Preferably the average volume of the bioactive CFC-12 1.287 CFC-114 1.288 agent/excipient shell or matrix (i.e. the Volume of medium PFOB 1.30S actually displaced by the perforated microstructure) com Mannitol 1.333 prises less than 70% of the average particle volume (or less Ethanol 1.361 than 70% of the virtual particle). More preferably, the Il-Octane 1.397 Volume of the microparticulate matrix comprises less than DMPC 1.43 Pluronic F-68 1.43 about 50%, 40%, and 30% or even 20% of the average Sucrose 1.538 particle volume. Even more preferably the average volume Hydroxyethylstarch 1.54 of the shell/matrix comprises less than about 10%, 5% or 3% Sodium chloride 1544 of the average particle volume. Those skilled in the art will appreciate that such a matrix or shell Volumes typically contributes little to the virtual particle density which is 0024 Consistent with the compatible dispersion compo overwhelmingly dictated by the Suspension medium found nents set forth above, those skilled in the art will appreciate therein. Of course, in selected embodiments the excipients that the formation of dispersions wherein the components used to form the perforated microstructure may be chosen So have a refractive index differential of less than about 0.5 is the density of the resulting matrix or shell approximates the preferred. That is, the refractive index of the suspension density of the Surrounding Suspension medium. medium will preferably be within about 0.5 of the refractive index associated with the perforated particles or microstruc 0027. It will be appreciated that the use of such micro tures. It will further be appreciated that the refractive index structures will allow the apparent density of the virtual of the Suspension medium and the particles may be mea particles to approach that of the Suspension medium Sub Sured directly or approximated using the refractive indices stantially eliminating the attractive van der Waals forces. of the major component in each respective phase. For the Moreover, as previously discussed, the components of the perforated microstructures, the major component may be microparticulate matrix are preferably selected, as much as determined on a weight percent basis. For the suspension possible given other considerations, to approximate the medium, the major component will typically be derived on density of Suspension medium. Accordingly, in preferred a volume percentage basis. In selected embodiments of the embodiments of the present invention the virtual particles present invention the refractive index differential value will and the suspension medium will have a density differential preferably be less than about 0.45, about 0.4, about 0.35 or of less than about 0.6 g/cm. That is, the mean density of the even less than about 0.3. Given that lower refractive index virtual particles (as defined by the matrix boundary) will be differentials imply greater dispersion stability, particularly within approximately 0.6 g/cm of the suspension medium. preferred embodiments comprise index differentials of less More preferably, the mean density of the virtual particles than about 0.28, about 0.25, about 0.2, about 0.15 or even will be within 0.5, 0.4, 0.3 or 0.2 g/cm of the selected less than about 0.1. It is submitted that a skilled artisan will Suspension medium. In even more preferable embodiments be able to determine which excipients are particularly com the density differential will be less than about 0.1, 0.05, 0.01, patible without undue experimentation given the instant or even less than 0.005 g/cm. disclosure. The ultimate choice of preferred excipients will 0028. In addition to the aforementioned advantages, the also be influenced by other factors, including biocompat use of hollow, porous particles allows for the formation of ibility regulatory status, ease of manufacture and cost. free-flowing dispersions comprising much higher volume 0025. In contrast to prior art attempts to provide stabi fractions of particles in Suspension. It should be appreciated lized Suspensions which require Surfactants that are soluble that the formulation of prior art dispersions at volume in the Suspension medium, the present invention provides fractions approaching close-packing generally results in for stabilized dispersions, at least in part, by immobilizing dramatic increases in dispersion viscoelastic behavior. the bioactive agent(s) and excipients (including Surfactants) Rheological behavior of this type is counterproductive in the within the structural matrix of the hollow, porous micro administration of bioactive agents. Those skilled in the art structures. Accordingly, preferred excipients useful in the will appreciate that, the volume fraction of the particles may present invention are Substantially insoluble in the Suspen be defined as, the ratio of the apparent volume of the sion medium. Under Such conditions, even Surfactants like, particles (i.e. the particle volume), to the total volume of the for example, lecithin cannot be considered to have Surfactant system. Each system has a maximum volume fraction or properties in the present invention since Surfactant perfor packing fraction. For example, particles in a simple cubic mance requires the amphiphile to be reasonably soluble in arrangement reach a maximum packing fraction of 0.52 the Suspension medium. The use of insoluble excipients also while those in a face centered cubic/hexagonal close packed reduces the potential for particle growth by Ostwald ripen configuration reach a maximum packing fraction of approxi 1ng. mately 0.74. For non-spherical particles or polydisperse systems, the derived values are different. Accordingly, the 0026. As alluded to above, the minimization of density maximum packing fraction is often considered to be an differences between the particles and the continuous phase is empirical parameter for a given system. largely dependent on the perforated and/or hollow nature of the microstructures, such that the Suspension medium con 0029. Here, it was surprisingly found that the porous stitutes most of the particle volume. As used herein, the term structures of the present invention do not exhibit undesirable US 2007/0212405 A1 Sep. 13, 2007

Viscoelastic behavior even at high Volume fractions, medium. One relatively simple way to determine the cream approaching close packing. To the contrary, they remain as ing time of a preparation is to provide a particulate Suspen free flowing, low viscosity Suspensions having little or no sion is sealed glass vials. The vials are agitated or shaken to yield stress when compared with analogous Suspensions provide relatively homogeneous dispersions which are then comprising solid particulates. The low viscosity of the set aside and observed: using appropriate instrumentation or disclosed Suspensions is thought to be due, at least in large by eye. The time necessary for the Suspended particulates to part, to the relatively low VDW attraction, between the cream to /2 the Volume of the Suspension medium (i.e. to rise fluid-filled hollow, porous particles. As such, in selected to the top half of the Suspension medium) or to sediment embodiments the volume fraction of the disclosed disper within /2 the volume (i.e. to settle in the bottom half of the sions is greater than approximately 0.3. Other embodiments medium) is then noted. Suspension formulations having a may have packing values on the order of 0.3 to about 0.5 or creaming time greater than 1 minute are preferred and on the order of 0.5 to about 0.8, with the higher values indicates suitable stability. More preferably, the stabilized approaching a close packing condition. Moreover, as par dispersions comprise creaming times of greater than about 2, ticle sedimentation tends to naturally decrease when the 5, 10, 15, 20 or 30 minutes. In particularly preferred embodi Volume fraction approaches close packing, the formation of ments the stabilized dispersions exhibit creaming times of relatively concentrated dispersions may further increase greater than about 1, 1.5, 2, 2.5, 3, 4 or even 5 hours. formulation stability. Substantially equivalent periods for sedimentation times are 0030 Although the methods and compositions of the similarly indicative of compatible dispersions. present invention may be used to form relatively concen 0033 Regardless of the ultimate composition or precise trated Suspensions the stabilizing factors work equally well creaming time, the stabilized respiratory dispersions of the at much lower packing Volumes and Such dispersions are present invention comprise a plurality of perforated micro contemplated as being within the scope of the instant structures or nicroparticulates that are dispersed or Sus disclosure. In this regard it will be appreciated that disper pended in the suspension medium. Preferably the perforated sions comprising low volume fractions are extremely diffi microstructures comprise a structural matrix that exhibits, cult to stabilize using prior art techniques. Conversely, defines or comprises voids, pores, defects, hollows, spaces, dispersions incorporating perforated microstructures com interstitial spaces, apertures, perforations or holes that prising a bioactive agent as described herein are particularly allows the Surrounding Suspension medium to freely perme stable even at low Volume fractions. Accordingly, the ate, fill or pervade the microstructure. The absolute shape (as present invention allows for stabilized dispersions, and opposed to the morphology) of the perforated microstructure particularly respiratory dispersions, to be formed and used at is generally not critical and any overall configuration that volume fractions less than 0.3. In some preferred embodi provides the desired Stabilization characteristics is contem ments the volume fraction is approximately 0.0001-0.3, plated as being within the scope of the invention. Accord more preferably 0.001-0.01. Yet other preferred embodi ingly, while preferred embodiments can comprise approxi ments comprise stabilized suspensions having Volume frac mately microspherical shapes, collapsed, deformed or tions from approximately 0.01 to approximately 0.1. fractured particulates are also compatible. With this caveat, it will be appreciated that particularly preferred embodi 0031. The perforated microstructures of the present ments of the invention comprise spray dried hollow, porous invention may also be used to stabilize dilute Suspensions of ionospheres. micronized bioactive agents. In Such embodiments the per 0034. In order to maximize dispersion stability and opti forated microstructures may be added to increase the volume mize bioavailability upon administration; the mean geomet fraction of particles in the Suspension, thereby increasing ric particle size of the perforated microstructures is prefer Suspension stability to creaming or sedimentation. Further, ably about 0.5-50 um, more preferably 1-30 Lum. Unlike in these embodiments the incorporated microstructures may aerosolization techniques, liquid dose instillation or admin also act in preventing close approach (aggregation) of the istration of bioactive agents does not depend critically on the micronized drug particles. It should be appreciated that the aerodynamic properties of the particle for efficient biodis perforated microstructures incorporated in Such embodi tribution. Rather, the unique wettability characteristics of the ments do not necessarily comprise a bioactive agent. Rather, FC Suspension medium and the homogeneous nature of the they may be formed exclusively of various excipients, dispersion promotes efficient biodistribution. Thus, there including Surfactants. may be some advantage to using larger particles (i.e. 5-30 0032. As indicated throughout the instant specification um) for this application, since recent studies (Edwards et al., the dispersions of the present invention are preferably sta Science 1997, 276:1868-1871, which is incorporated herein bilized. In a broad sense, the term “stabilized dispersion by reference) have suggested that large porous particles may will be held to mean any dispersion that resists aggregation, be able to provide a sustained release of bioactive agent. flocculation or creaming to the extent required to provide for Edwards et al. claim that their large porous particles are the effective delivery of a bioactive agent. While those effective Sustained release agents upon inhalation because skilled in the art will appreciate that there are several they are too large to be effectively cleared by pulmonary methods that may be used to assess the stability of a given macrophages, yet light enough to penetrate deep into the Suspension, a preferred method for the purposes of the lung, thereby avoiding clearance by the mucociliary esca present invention comprises determination of creaming or lator. In this regard it will be appreciated that the composi sedimentation time. In this regard, the creaming time shall tions and methods of the present invention may provide for be defined as the time for the suspended drug particulates to the deep lung deposition of the bioactive particulates thereby cream to /2 the volume of the suspension medium. Similarly, countering, at least in part, the mucociliary escalator. the sedimentation time may be defined as the time it takes Accordingly, larger perforated microstructures having a geo for the particulates to sediment in /2 the volume of the liquid metric diameter of greater than approximately 5 um may US 2007/0212405 A1 Sep. 13, 2007

prove to be particularly effective when administered (i.e. by late material may be coated one or more times with poly LDI using the disclosed dispersions. mers, Surfactants or other compounds which aid Suspension. 0035 Besides the aforementioned advantages, there may 0039 More generally, the perforated microstructures be significant differences in local versus systemic bioavail may be formed of any biocompatible material that is rela ability depending upon the size of the hollow porous par tively stable and preferably insoluble with respect to the ticles delivered via liquid dose instillation. For example it is selected Suspension medium and can provide the necessary easy to envision that Smaller particles (ca. 1 um) may be perforated configuration. While a wide variety of materials more efficiently delivered to the alveolus than large particles may be used to form the particles, in particularly preferred (ca. 20 um). The choice of particle size will ultimately be embodiments the structural matrix is associated with, or dependent on the nature of the bioactive agent and its comprises, a Surfactant such as phospholipid or fluorinated intended site of action. In especially preferred embodiments Surfactant. Although not required, the incorporation of a the perforated microstructures will comprise a powder of compatible surfactant can improve the stability of the res dry, hollow, porous microspherical shells of approximately piratory dispersions, increase pulmonary deposition and 1 to 30 um in diameter, with shell thicknesses of approxi facilitate the preparation of the suspension. Moreover, by mately 0.1 um to approximately 0.5 Lum. It is a particular altering the components, the density of the structural matrix advantage of the present invention that the particulate con may be adjusted to approximate the density of the Surround centration of the dispersions and structural matrix compo ing medium and further stabilize the dispersion. Finally, as nents can be adjusted to optimize the delivery characteristics will be discussed in further detail below, the perforated of the selected particle size. microstructures preferably comprise at least one bioactive agent. 0036) As alluded to throughout the instant specification the porosity of the microstructures may play a significant 0040. As set forth above the perforated microstructures of part is establishing dispersion stability. In this respect, the the present invention may optionally be associated with, or mean porosity of the perforated microstructures may be comprise, one or more surfactants. Moreover, miscible Sur determined through electron microscopy coupled with mod factants may optionally be combined with the Suspension ern imaging techniques. More specifically, electron micro medium liquid phase. It will be appreciated by those skilled graphs of representative samples of the perforated micro in the art that the use of Surfactants, while not necessary to structures may be obtained and digitally analyzed to practice the instant invention, may further increase disper quantify the porosity of the preparation. Such methodology sion stability, simplify formulation procedures or increase is well known in the art and may be undertaken without bioavailability upon administration. With respect to metered undue experimentation. dose makers (MDls) surfactants further serve to lubricate the metering valve, thereby ensuring consistent reproducibility 0037 For the purposes of the present invention, the mean of valve actuation and accuracy of dose dispersed. Of course porosity (i.e. the percentage of the particle Surface area that combinations of Surfactants, including the use of one or is open to the interior and/or a central void) of the perforated more in the liquid phase and one or more associated with the microstructures may range from approximately 0.5% to perforated microstructures are contemplated as being within approximately 80%. In more preferred embodiments, the the scope of the invention. By “associated with or comprise' mean porosity will range from approximately 2% to it is meant that the structural matrix or perforated micro approximately 40%. Based on selected production param structure may incorporate, adsorb, absorb, be coated with or eters, the mean porosity may be greater than approximately, be formed by the surfactant. 2%. 5%, 10%, 15%, 20%, 25% or 30% of the microstructure Surface area. In other embodiments, the mean porosity of the 0041. In a broad sense surfactants suitable for use in the microstructures may be greater than about 40%, 50%, 60%, present invention include any compound or composition that 70% or even 80%. As to the pores themselves, they typically aids in the formation and maintenance of the stabilized range in size from about 5 nm, to about 400 nm, with mean respiratory dispersions by forming a layer at the interface pore sizes preferably in the range of from about 20 nm, to between the structural matrix and the Suspension medium. about 200 nm. In particularly preferred embodiments the The Surfactant may comprise a single compound or any mean pore size will be in the range of from about 50 nm to combination of compounds, such as in the case of co about 100 nm. surfactants. Particularly preferred surfactants are substan tially insoluble in the propellant, nonfluorinated, and 0038 Whatever configuration and/or size distribution is selected from the group consisting of Saturated and unsat ultimately selected for the perforated microstructure, the urated lipids, nonionic detergents, nonionic block copoly composition of the defining structural matrix may comprise mers, ionic Surfactants, and combinations of Such agents. It any one of a number of biocompatible materials. It will be should be emphasized that, in addition to the aforemen appreciated that, as used herein, the terms "structural tioned surfactants, suitable (i.e. biocompatible) fluorinated matrix' or “microstructure matrix” are equivalent and shall Surfactants are compatible with the teachings herein and be held to mean any solid material forming the perforated may be used to provide the desired stabilized preparations. microstructures which define a plurality of Voids, apertures, hollows, defects, pores, holes, fissures, etc. that promote the 0042 Lipids, including phospholipids, from both natural formation of stabilized dispersions as explained above. The and synthetic sources are particularly compatible with the structural matrix may be soluble or insoluble in an aqueous present invention and may be used in varying concentrations environment. In preferred embodiments the perforated to form the structural matrix. Generally compatible lipids microstructure defined by the structural matrix comprises a comprise those that have a gel to liquid crystal phase spray dried hollow porous microsphere incorporating at least transition greater than about 40° C. Preferably the incorpo one surfactant. For other selected embodiments the particu rated lipids are relatively long chain (i.e. C-C) saturated US 2007/0212405 A1 Sep. 13, 2007 lipids and more preferably comprise phospholipids. Exem high levels of surfactant. In this regard, the perforated plary phospholipids useful in the disclosed stabilized prepa microstructures will preferably comprise greater than about rations comprise egg phosphatidylcholine, dilauroylphos 1%, 5%, 10%, 15%, 18%, or even 20% w/w surfactant. phatidylcholine, dioleylphosphatidylcholine, More preferably, the perforated microstructures will com dipalmitoylphosphatidyl-choline, disteroylphosphatidylcho prise greater than about 25%, 30%, 35%, 40%, 45%, or 50% line, short-chain phosphatidylcholines, phosphatidylethano w/w surfactant. Still other exemplary embodiments will lamine, dioleylphosphatidylethanolamine, phosphati dylserine, phosphatidylglycerol, phosphatidylinositol, comprise perforated microstructures wherein the Surfactant glycolipids, ganglioside GM1, Sphingomyelin, phosphatidic or surfactants are present at greater than about 55%, 60%, acid, cardiolipin; lipids bearing polymer chains such as 65%, 70%, 75%, 80%, 85%, 90% or even 95% w/w. In polyethylene glycol, chitin, hyaluronic acid, or polyvi selected embodiments the perforated microstructures will nylpyrrolidone; lipids bearing Sulfonated mono-, di-, and comprise essentially 100% w/w of a surfactant such as a polysaccharides; fatty acids such as palmitic acid, Stearic phospholipid. Those skilled in the art will appreciate that, in acid, and oleic acid; cholesterol, cholesterol esters, and Such cases, the balance of the structural matrix (where cholesterol hemisuccinate. Due to their excellent biocom applicable) will preferably comprise a bioactive agent or non patibility characteristics, phospholipids and combinations of Surface active excipients or additives. phospholipids and poloxamers are particularly Suitable for 0047 While such surfactant levels are preferably use in the stabilized dispersions disclosed herein. employed in perforated microstructures, they may be used to 0.043 Compatible nonionic detergents comprise: sorbitan provide stabilized systems comprising relatively nonporous, esters including sorbitan trioleate (Spans(R 85), sorbitan or substantially solid, particulates. That is, while preferred sesquioleate, Sorbitan monooleate, Sorbitan monolaurate, embodiments will comprise perforated microstructures or polyoxyethylene (20) Sorbitan monolaurate, and polyoxy microspheres associated with high levels of Surfactant, ethylene (20) sorbitan monooleate, oleyl polyoxyethylene acceptable dispersions may be formed using relatively low (2) ether, Stearyl polyoxyethylene (2) ether, lauryl polyoxy porosity particulates of the same Surfactant concentration ethylene (4) ether, glycerol esters, and Sucrose esters. Other (i.e. greater than about 10% or 20% w/w). In this respect Suitable nonionic detergents can be easily identified using Such embodiments are specifically contemplated as being McCutcheon's Emulsifiers and Detergents (McPublishing within the scope of the present invention. Co., Glen Rock, N.J.) which is incorporated herein in its 0048. In other preferred embodiments of the invention entirety. Preferred block copolymers include diblock and the structural matrix defining the perforated microstructure triblock copolymers of polyoxyethylene and polyoxypropy optionally comprises synthetic or natural polymers or com lene, including poloxamer 188 (Pluronic RF-68), poloxamer binations thereof In this respect useful polymers comprise 407 (PluroniR) F-127), and poloxamer 338. Ionic surfactants polylactides, polylactide-glycolides, cyclodextrins, poly Such as Sodium sulfo Succinate, and fatty acid soaps may also acrylates, methylcellulose, carboxymethylcellulose, polyvi be utilized. In preferred embodiments the microstructures nyl alcohols, polyanhydrides, polylactams, polyvinyl pyr may comprise oleic acid or its alkali salt. rolidones, polysaccharides (dextrans, starches, chitin, 0044) In addition to the aforementioned surfactants, cat chitosan, etc.), hyaluronic acid, proteins, (albumin, collagen, ionic Surfactants or lipids are preferred especially in the case gelatin, etc.). Those skilled in the art will appreciate that, by of delivery or RNA or DNA. Examples of suitable cationic selecting the appropriate polymers, the delivery profile of lipids include: DOTMA, N-1-(2,3-dioleyloxy)propyl-N,N. the respiratory dispersion may be tailored to optimize the N-trimethylammonium chloride: DOTAP 1,2-dioleyloxy effectiveness of the bioactive agent. 3-(trirnethylammonio)propane; and DOTB, 1,2-dioleyl-3- 0049 Besides the aforementioned polymer materials and (4'-trimethylammonio)butanoyl-sn-glycerol. Polycationic Surfactants it may be desirable to add other excipients to an amino acids such as polylysine, and polyarginine are also aerosol formulation to improve microsphere rigidity, drug contemplated. delivery and deposition, shelf-life and patient acceptance. 0045 Those skilled in the art will further appreciate that Such optional excipients include, but are not limited to: a wide range of Surfactants may optionally be used in coloring agents, taste masking agents, buffers, hygroscopic conjunction with the present invention. Moreover, the opti agents, antioxidants, and chemical stabilizers. Further, Vari mum Surfactant or combination thereof for a given applica ous excipients may be incorporated in, or added to, the tion can readily be determined by empirical studies that do particulate matrix to provide structure and form to the not require undue experimentation. It will further be appre perforated microstructures (i.e. microspheres). These excipi ciated that the preferred insolubility of any incorporated ents may include, but are not limited to, carbohydrates Surfactant in the Suspension medium will dramatically including monosaccharides, disaccharides and polysaccha decrease the associated Surface activity. As such, it is argu rides. For example, monosaccharides Such as dextrose able as to whether these materials have surfactant-like (anhydrous and monohydrate), galactose, mannitol, D-man character prior to contracting an aqueous bioactive Surface nose, Sorbitol, Sorbose and the like, disaccharides Such as (e.g. the aqueous hypophase in the lung). Finally, as dis lactose, maltose, Sucrose, trehalose, and the like; trisaccha cussed in more detail below, Surfactants comprising the rides such as raffinose and the like; and other carbohydrates porous particles may also be useful in the formation of Such as starches (hydroxyethylstarch), cyclodextrins and precursor oil-in-water emulsions (i.e. spray drying feed maltodextrins. Amino acids are also suitable excipients with stock) used during processing to form the structural matrix. glycine preferred. Mixtures of carbohydrates and amino acids are further held to be within the scope of the present 0046. On a weight to weight basis, the structural matrix invention. The inclusion of both inorganic (e.g. sodium of the perforated microstructures may comprise relatively chloride, calcium chloride), organic salts (e.g. sodium cit US 2007/0212405 A1 Sep. 13, 2007 rate, Sodium ascorbate, magnesium gluconate, Sodium glu 0053. It will be appreciated that the distributed particles conate, tromethamine hydrochloride) and buffers is also or perforated microstructures of the present invention may contemplated. exclusively comprise one or more bioactive agents (i.e. 100% w/w). However, in selected embodiments the particles 0050 Yet other preferred embodiments include perfo or perforated microstructures may incorporate much less rated microstructures that may comprise, or may be coated bioactive agent depending on the activity thereof. Accord with, charged species that prolong residence time at the ingly, for highly active materials, the particles may incor point of contact or enhance penetration through mucosae. porate as little as 0.001% by weight, although a concentra For example, anionic charges are known to favor mucoad tion of greater than about 0.1% w/w is preferred. Other hesion, while cationic charges may be used to associate the embodiments of the invention may comprise greater than formed microparticulate with negatively charged bioactive about 5%, 10%, 15%, 20%, 25%, 30% or, even 40% w/w agents such as genetic material. The charges may be bioactive agent. Still more preferably the particles or per imparted though the association or incorporation of polya forated microstructures may comprise greater than about nionic or polycationic materials such as polyacrylic acids, 50%, 60%, 70%, 75%, 80% or, even 90% w/w bioactive polylysine, polylactic acid and chitosan. agent. In particularly preferred embodiments the final sta bilized respiratory dispersion desirably contains from about 0051. In addition to, or instead of, the components dis 40%-60% w/w, more preferably 50%–70% w/w, and even cussed above, the perforated microstructures will preferably more preferably 60%-90% w/w of bioactive agent relative to comprise at least one bioactive agent. As used herein, the weight of the microparticulate matrix or particulate. The “bioactive agent” refers to a substance which is used in precise amount of bioactive agent incorporated in the sta connection with an application that is therapeutic or diag bilized dispersions of the present invention is dependent nostic in nature, such as in methods for diagnosing the upon the agent of choice, the Volume of Suspension media presence or absence of a disease in a patient and/or in required to effectively distribute the drug, the required dose methods for treating a disease in a patient. As to compatible and the form of the drug actually used for incorporation. bioactive agents, those skilled in the art will, appreciate that Those skilled in the art will appreciate that, such determi any therapeutic or diagnostic agent may be incorporated in nations may be made by using well known pharmacological the stabilized dispersions of the present invention. For techniques, in combination with the teachings of the present example, the bioactive agent may be selected from the group invention. consisting of antiallergics, bronchodilators, bronchocon 0054 Accordingly, bioactive agents that are suitable for strictors, pulmonary lung Surfactants, analgesics, antibiotics, pulmonary administration in conjunction with the teachings leukotriene inhibitors or antagonists, anticholinergics, mast herein include any drug that may be presented in a form cell inhibitors, antihistamines, antiintlammatories, antine which is relatively insoluble in the selected medium and oplastics, anesthetics, anti-tuberculars, imaging agents, car Subject to pulmonary uptake in physiologically effective diovascular agents, enzymes, steroids, genetic material, viral amounts. Compatible bioactive agents may comprise hydro vectors, antisense agents, proteins, peptides and combina philic and lipophilic respiratory agents, bronchodilators, tions thereof. Particularly preferred bioactive agents com pulmonary lung Surfactants, antibiotics, antivirals, anti-in prise compounds which are to be administered systemically flammatories, Steroids, antihistaminics, histamine antago (i.e. to the systemic circulation of a patient) Such as peptides, nists, leukotriene inhibitors or antagonists, anticholinergics, proteins or polynucleotides. As will be disclosed in more antineoplastics, anesthetics, enzymes, lung Surfactants, car detail below, the bioactive agent may be incorporated, diovascular agents, genetic material including DNA and blended in, coated on or otherwise associated with the RNA, viral vectors, immunoactive agents, imaging agents, perforated microstructure. Particularly preferred bioactive vaccines, immunosuppressive agents, peptides, proteins and agents for use in accordance with the invention include combinations thereof. Particularly preferred bioactive anti-allergics, peptides and proteins, bronchodilators and agents, for localized administration include mast cell inhibi anti-inflammatory steroids for use in the treatment of respi tors (anti-allergics), bronchodilators, and anti-inflammatory ratory disorders such as asthma by inhalation therapy. Yet steroids for use in the treatment of respiratory disorders such another associated advantage of the present invention is the as asthma by inhalation therapy, i.e. cromoglycate (e.g. the effective delivery of bioactive agents. Sodium salt), and albuterol (e.g. the Sulfate salt). For sys 0.052 With respect to particulate dispersions, the selected temic delivery (e.g. for the treatment of autoimmune dis bioactive agent, or agents, may be used as the sole structural eases such as diabetes or multiple Sclerosis), peptides and component of the perforated microstructures. Conversely, proteins are particularly preferred. the perforated microstructures may comprise one or more 0055 Exemplary medicaments or bioactive agents may components (i.e. structural materials, Surfactants, excipients, be selected from, for example, analgesics, e.g. codeine, etc.) in addition to the incorporated bioactive agents. In dihydromorphine, ergotamine, fentanyl, or morphine; angi particularly preferred embodiments, the suspended perfo nal preparations, e.g. diltiazem; mast cell inhibitors, e.g. rated microstructures will comprise relatively high concen cromolyn Sodium; antiinfectives, e.g. cephalosporins, mac trations of surfactant (greater than about 10% w/w) along rolides, quinolines, penicillins, Streptomycin, Sulphona with the incorporated bioactive agent(s). Finally, it should be mides, tetracyclines and pentamidine; antihistamines, e.g. appreciated that the particulate or perforated microstructure methapyrilene; anti-inflammatories, e.g. fluticaSone propi may be coated, linked or otherwise associated with the onate, beclomethasone dipropionate, flunisolide, budes bioactive agent in a non-integral manner. Whatever configu onide, tripedane, cortisone, prednisone, prednisilone, dex ration is selected, it will be appreciated that the associated amethasone, betamethasone, or triamcinolone acetonide; bioactive agent may be used in its natural form, or as one or antitussives, e.g. noscapine; bronchodilators, e.g. ephedrine, more salts known in the art. adrenaline, fenoterol, formoterol, isoprenaline, metaproter US 2007/0212405 A1 Sep. 13, 2007

enol, salbutamol, albuterol, salmeterol, terbutaline; diuret amount of bioactive agent and the timing of the dosages may ics, e.g. amiloride; anticholinergics, e.g. ipatropium, atro be determined for the formulations in accordance with pine, or oxitropium; lung Surfactants e.g. Surfaxin, ExoSurf already-existing information and without undue experimen Survanta, Xanthines, e.g. aminophylline, theophylline, caf tation. feine; therapeutic proteins and peptides, e.g. DNAse, insu lin, glucagon, T-cell receptoragonists orantagonists, LHRH, 0059. As seen from the passages above, various compo nafarelin, goserelin, leuprolide, interferon, rhu IL-1 recep nents may be associated with, or incorporated in the perfo tor, macrophage activation factors such as lymphokines and rated microstructures of tie present invention. Similarly, muramyl dipeptides, opioid peptides and neuropeptides Such several techniques may be used to provide particulates as enkaphalins, endorphins, renin inhibitors, cholecystoki having the desired morphology (e.g. a perforated or hollow/ nins, growth hormones, leukotriene inhibitors, C.-antit porous configuration) and density. Among other methods, rypsin, and the like. In addition, bioactive agents that perforated microstructures compatible with the instant comprise an RNA or DNA sequence, particularly those invention may be formed by techniques including lyo useful for gene therapy, genetic vaccination, genetic toler philization, spray drying, multiple emulsion, micronization, ization or antisense applications, may be incorporated in the or crystallization. It will further be appreciated that the basic disclosed dispersions as described herein. Representative concepts of many of these techniques area well known in the DNA plasmids include, but are not limited to pCMVB prior art and would not, in view of the teachings herein, (available from Genzyme Corp, Framington, Mass.) and require undue experimentation to adapt them so as to pCMV-B-gal (a CMV promotor linked to the E. coli Lac-Z provide the desired perforated microstuctures. gene, which codes for the enzyme B-galactosidase). 0060. While several procedures are generally compatible 0056 With respect to particulate dispersions, the selected with the present invention, particularly preferred embodi bioactive agent(s) may be associated with, or incorporated ments typically comprise perforated microstructures formed in, the particles or perforated microstructures in any form by spray drying. As is well known, spray drying is a one-step that provides the desired efficacy and is compatible with the process that converts a liquid feed to a dried particulate chosen production techniques. Similarly, the incorporated form. With respect to pharmaceutical applications, it will be bioactive agent may be associated with the discontinuous appreciated that spray drying has been used to provide phase of a reverse emulsion. As used herein, the terms powdered material for various administrative routes includ “associate' or “associating” mean that the structural matrix, ing inhalation. See, for example, M. Sacchetti and M. M. perforated microstructure, relatively non-porous particleor Van Oort in: Inhalation Aerosols: Physical and Biological discontinuous phase may comprise, incorporate, adsorb, Basis for Therapy, A. J. Hickey, ed. Marcel Dekkar, New absorb, be coated with, or be formed by the bioactive agent. York, 1996, which is incorporated herein by reference. Where appropriate, the medicaments may be used in the 0061. In general, spray drying consists of bringing form of salts (e.g. alkali metal or amine salts or as acid together a highly dispersed liquid and a sufficient volume of addition salts), or as esters, or as Solvates (hydrates). In this hot air to produce evaporation and drying of the liquid regard, the form of the bioactive agents may be selected to droplets. The preparation to be spray dried or feed (or feed optimize the activity and/or stability of the medicament stock) can be any solution, course Suspension, slurry, col and/or, to minimize the solubility of the medicament in the loidal dispersion, or paste that may be atomized using the Suspension medium. selected spray drying apparatus. Typically the feed is 0057. It will further be appreciated that formulations sprayed into a current of warm filtered air that evaporates the according to the invention may, if desired, contain a com solvent and conveys the dried product to a collector. The bination of two or more active ingredients. The agents may spent air is then exhausted with the solvent. Those skilled in be provided in combination in a single species of perforated the art will appreciate that several different types of appa microstructure or individually in separate species that are ratus may be used to provide the desired product. For combined in the Suspension medium or continuous phase. example, commercial spray dryers manufactured by Bichi For example, two or more bioactive agents may be incor Ltd. or Nird Corp. will effectively produce particles of porated in a single feed stock preparation and spray dried to desired size. It will further be appreciated that these spray provide a single microstructure species comprising a plu dryers, and specifically their atomizers, may be modified or rality of medicaments. Conversely, the individual medica customized for specialized applications, e.g. the simulta ments could be added to separate stocks and spray dried neous spraying of two solutions using a double nozzle separately to provide a plurality of microstructure species technique. More specifically, a water-in-oil emulsion can be with different compositions. These individual species could atomized from one nozzle and a solution containing an be added to, the medium in any desired proportion and anti-adherent Such as mannitol can be co-atomized from a placed in delivery systems as described below. Further, as second nozzle. In other cases it may be desirable to push the briefly alluded to above, the perforated microstructures feed solution though a custom designed noZZle using a high (with or without an associated medicament) may be com pressure liquid chromatography (HPLC) pump. Provided bined with one or more conventionally micronized bioactive that microstructures comprising the correct morphology agents to provide the desired dispersion stability. and/or composition are produced the choice of apparatus is not critical and would be apparent to the skilled artisan in 0.058 Based on the foregoing, it will be appreciated by view of the teachings herein. those skilled in the art that a wide variety of bioactive agents may be incorporated in the disclosed stabilized dispersions. 0062) While typical spray-dried particles are approxi Accordingly, the list of preferred bioactive agents above is mately spherical in shape, nearly uniform in size and fre exemplary only and not intended to be limiting. It will also quently hollow, there may be some degree of irregularity in be appreciated by those skilled in the art that, the proper shape depending upon the incorporated medicament and the US 2007/0212405 A1 Sep. 13, 2007 spray drying conditions. In many instances the dispersion 0065 While not limiting the invention in any way it is stability of spray-dried microspheres appears to be more hypothesized that, as the aqueous feed component evapo effective if an inflating agent (or blowing agent) is used in rates during spray drying it leaves a thin crust at the Surface their production. Particularly preferred embodiments may of the particle. The resulting particle wall or crust formed comprise, an emulsion with the inflating agent as the dis during the initial moments of spray drying appears to trap perse or continuous phase (the other phase being aqueous in any high boiling blowing agents as hundreds of emulsion nature). The inflating agent is preferably dispersed with a droplets (ca. 200-300 nm). As the drying process continues, Surfactant Solution, using, for instance, a commercially the pressure inside the particulate increases thereby vapor available microfluidizer at a pressure of about 5000 to izing at least part of the incorporated blowing agent and 15,000 psi. This process forms an emulsion, preferably forcing it through the relatively thin crust. This venting or stabilized by an incorporated Surfactant, typically compris outgassing apparently leads to the formation of pores or ing Submicron droplets of water immiscible blowing agent other defects in the crust. At the same time, remaining dispersed in an aqueous continuous phase. The formation of particulate components (possibly including some blowing Such dispersions using this and other techniques are com agent) migrate from the interior to the Surface as the particle mon and well known to those in the art. The blowing agent Solidifies. This migration apparently slows during the drying is preferably a fluorinated compound (e.g. perfluorohexane, process as a result of increased resistance to mass transfer perfluorooctyl bromide, perfluorodecalin, perfluorobutyl caused by an increased internal viscosity. Once the migra ethane) which vaporizes during the spray-drying process, tion ceases the particle solidifies, leaving vesicles, vacuoles leaving behind generally hollow, porous, aerodynamically or voids where the emulsifying agent resided. The number of light microspheres. As will be discussed in more detail pores, their size, and the resulting wall thickness is largely below, other suitable blowing agents include chloroform, dependent on the nature of the selected blowing agent (i.e. Freons and hydrocarbons. Nitrogen gas and carbon dioxide boiling point), its concentration in the emulsion, total Solids are also contemplated as a Suitable blowing agent. concentration, and the spray-drying conditions. 0063 Although the perforated microstructures are pref 0066. It has been surprisingly found that substantial erably formed using a blowing agent as described above, it amounts of these relatively high boiling blowing agents may will be appreciated that, in some instances, no blowing agent be retained in the resulting spray dried product. That is, the is required and an aqueous dispersion of the medicament and spray dried perforated microstructures may comprise as Surfactant(s) are spray dried directly. In Such cases, the much as 5%, 10%, 20%, 30% or even 40% w/w of the formulation may be amenable to process conditions (e.g., blowing agent. In such cases, higher production yields were elevated temperatures) that generally lead to the formation obtained as a result an increased particle density caused by of hollow, relatively porous microparticles. Moreover, the residual blowing agent. It will be appreciated by those medicament may possess special physicochemical proper skilled in the art that this retained fluorinated blowing agent ties such as, high in crystaminity, elevated melting tempera may alter the surface characteristics of the perforated micro ture, Surface activity, etc., that make it particularly suitable structures and further increase the stability of the respiratory for use in Such techniques. dispersions. Conversely, the residual blowing agent can 0064. When a blowing agent is employed, the degree of generally be removed relatively easily with a post-produc porosity of the perforated microstructure appears to depend, tion evaporation step in a vacuum oven. Optionally, pores at least in part, on the nature of the blowing agent, its may be formed by spray drying a bioactive agent and an concentration in the feed stock (i.e. as an emulsion), and the excipient that can be removed from the formed microspheres spray drying conditions. With respect to controlling porosity under a vacuum. it has Surprisingly been found that the use of compounds, 0067. In any event, typical concentrations of blowing heretofore unappreciated as blowing agents, may provide agent in the feed stock are between 5% and 100% w/v, and perforated microstructures having particularly desirable more preferably between about 20% to 90% w/v. In other characteristics. More particularly, in this novel and unex embodiments blowing agent concentrations will preferably pected aspect of the present invention it has been found that be greater than about 10%, 20%, 30%, 40% 50% or even the use of fluorinated compounds having relatively high 60% w/v. Yet other feed stock emulsions may comprise boiling points (i.e. greater than about 60° C.) may be used 70%, 80%, 90% or even 95% w/v of the selected high to produce particulates that are especially suitable for inha boiling point compound. lation therapies. In this regard it is possible to use fluorinated blowing agents having boiling points of greater than about 0068. In preferred embodiments, another method of iden 70° C., 80° C., 90° C. or even 95° C. Particularly preferred tifying the concentration of blowing agent used in the feed blowing agents have boiling points greater than the boiling is to provide it as a ratio of the concentration of the blowing point of water, i.e. greater than 100° C. (e.g. perflubron, agent to that of the stabilizing Surfactant (i.e. phospholipid) perfluorodecalin). In addition, blowing agents with rela in the precursor emulsion. For fluorocarbon blowing agents tively low water solubility (<10 M) are preferred since such as perfluorooctyl bromide and phosphatidylcholine, the they enable the production of stable emulsion dispersions ratio may be termed a perfluorocarboni/phosphatidylcholine with mean weighted particle diameters less than 0.3 um. As ratio (or PFC/PC ratio). While phosphotidylcholine is a indicated above, these blowing agents will preferably be preferred surfactant, those skilled in the art will appreciate incorporated in an emulsified feed Stock prior to spray that other Surfactants may provide acceptable emulsions and drying. For the purposes of the present invention this feed may be substituted therefore. In any event, the PFC/PC ratio stock will also preferably comprise one or more bioactive will typically range from about 1 to about 60 and more agents, one or more surfactants, or one or more excipients. preferably from about 10 to about 50. For preferred embodi Of course, combinations of the aforementioned components ments the ratio will, generally be greater than about 5, 10, are also within the scope of the invention. 20, 25, 30, 40 or even 50. In this respect, it will be US 2007/0212405 A1 Sep. 13, 2007 appreciated that higher PFC/PC ratios typically lead to mined through standard empirical testing; with due refer particulates exhibiting greater porosity. Accordingly, alter ence to the examples that follow. Of course, the conditions ing the PFC/PC ratio in the feed stock emulsion may may be adjusted so as to preserve biological activity in larger advantageously control the morphology of the resulting molecules such as proteins or peptides. microstructures. In this regard, the use of higher PFC/PC 0075 Particularly preferred embodiments of the present ratios tends to provide structures of a more hollow and invention comprise spray drying preparations comprising a porous nature. More particularly, those methods employing Surfactant such as a phospholipid and at least one bioactive a PFC/PC ratio of greater than about 4.8 tended to provide agent. In other embodiments the spray drying preparation structures that are particularly compatible with the disper may further comprise an excipient comprising a hydrophilic sions disclosed herein. moiety Such as, for example, a carbohydrate (i.e. glucose, 0069. While relatively high boiling point blowing agents lactose, or starch) in addition to any selected Surfactant. In comprise one preferred aspect of the instant invention, it will this regard various starches and derivatized starches Suitable be appreciated that more conventional blowing or inflating for use in the present invention. Other optional components agents may also be used to provide compatible perforated may include conventional viscosity modifiers buffers such as microstructures. Generally, the inflating agent can be any phosphate buffers or other conventional biocompatible buff material that will turn to a gas at Some point during the spray ers or pH adjusting agents such as acids or bases, and drying or post-production process. Suitable agents include: osmotic agents (to provide isotonicity, hyperosmolarity, or hyposmolarity). Examples of Suitable salts include sodium 0070) 1. Dissolved low-boiling (below 100° C.) solvents phosphate (both monobasic and dibasic), Sodium chloride, with limited miscibility with aqueous solutions, such as calcium phosphate, calcium chloride and other physiologi methylene chloride, acetone and carbon disulfide used to cally acceptable salts. Saturate the Solution at room temperature. 0076 Whatever components are selected, the first step in 0.071) 2. A gas, e.g. CO2 or N2, used to saturate the particulate production typically comprises feed stock prepa Solution at room temperature and levated pressure (e.g. 3 ration. Preferably the selected drug is dissolved in water to bar). The droplets are then supersaturated with the gas at produce a concentrated Solution. The drug may also be atmosphere and 100° C. dispersed directly in the emulsion, particularly in the case of 0072 3. Emulsions of immiscible low-boiling (below water insoluble agents. It will also be appreciated that the 100° C.) liquids such as Freon 113, perfluoropentane, drug may be incorporated in the form of a solid particulate perfluorohexane, perfluorobutane, pentane, butane, dispersion. The concentration of the a drug used is depen dent on the dose of drug required in the final powder and the FC-11, FC-11B1, FC-11B2, FC-12B2, FC-21, FC-21B1 performance of the MDI drug Suspension (e.g., fine particle FC-21B2, FC-31B1. FC113A, FC-122, FC-123, FC-132, dose). As needed, coSurfactants such as poloxamer 188 or FC-133, FC-141, FC-141B, FC-142, FC-151, FC-152, span 80 may be added to this annex solution. Additionally, FC-1112, FC-1121 and FC-1131. excipients such as Sugars and starches can also be added. 0.073 With respect to these lower boiling point inflating 0077. In selected embodiments an oil-in-water emulsion agents, they are typically added to the feed stock in quan is then formed in a separate vessel. The oil employed is tities of about 1% to 80% w/v of the surfactant solution. preferably a fluorocarbon (e.g., perfluorooctyl bromide, per Approximately 30% w/v inflating agent has been found to fluorodecalin) which is emulsified using a surfactant Such as produce a spray dried powder that may be used to form the a long chain Saturated phospholipid. For example, one gram stabilized dispersions of the present invention. of phospholipid may be homogenized in 150g hot distilled 0074 Regardless of which blowing agent is ultimately water (e.g., 60° C.) using a suitable high shear mechanical selected, it has been found that compatible perforated micro mixer (e.g., Ultra-Turrax model T-25 mixer) at 8000 rpm for structures may be produced particularly efficiently using a 2 to 5 minutes. Typically 5 to 25 g of fluorocarbon is added Büchi mini spray drier (model B-191; Switzerland). As will dropwise to the dispersed surfactant Solution while mixing. be appreciated by those skilled in the art, the inlet tempera The resulting perfluorocarbon in water emulsion is then ture and the outlet temperature of the spray drier are not processed using a high pressure homogenizer to reduce the critical but will be of such a level to provide the desired particle size. Typically the emulsion is processed at 12,000 particle size and to result in a product that has the desired to 18,000 psi for 5 discrete passes and kept at 50 to 80° C. activity of the medicament. In this regard, the inlet and outlet 0078. The drug solution and perfluorocarbon emulsion temperatures are adjusted depending on the melting charac are then combined and fed into the spray dryer. Typically the teristics of the formulation components and the composition two preparations will be miscible as the emulsion will of the feed stock. The inlet temperature may thus be between preferably comprise an aqueous continuous phase. While the 60° C. and 170° C., with the outlet temperatures of about 40° bioactive agent is solubilized separately for the purposes of C. to 120° C. depending on the composition of the feed and the instant discussion it will be appreciated that, in other the desired particulate characteristics. Preferably these tem embodiments, the bioactive agent may be solubilized (or peratures will be from 90° C. to 120° C. for the inlet and dispersed) directly in the emulsion. In Such cases, the from 60° C. to 90° C. for the outlet. The flow rate that is used bioactive emulsion is simply spray dried without combining in the spray drying equipment will generally be about 3 ml separate drug preparation. per minute to about 15 ml per minute. The atomizer air flow rate may vary between values of 1,200 liters per hour, to 0079. In any event, operating conditions such as inlet and about 3.900 liters per hour. Commercially available spray outlet temperature, feed rate, atomization pressure, flow rate dryers are well known to those in the art, and suitable of the drying air, and nozzle configuration can be adjusted in settings for any particular dispersion can be readily deter accordance with the manufacturer's guidelines in order to US 2007/0212405 A1 Sep. 13, 2007 produce the required particle size; and production yield of appreciated that the Suspension medium may comprise a the resulting dry microstructures. Exemplary settings are as mixture of various compounds selected to impart specific follows: an air inlet temperature between 60° C. and 170° characteristics. It will also be appreciated that the perforated C.; an air outlet between 40° C. to 120° C.; a feed rate microstructures are preferably insoluble in the Suspension between 3 ml to about 15 ml per minute; and an aspiration medium, thereby providing for stabilized medicament par setting of 100% and an atomization air flow rate between ticles, and effectively protecting a selected bioactive agent 1,200 to 2,800 L/hr. The selection of appropriate apparatus from degradation, as might occur during prolonged storage and processing conditions are well within the purview of a in an aqueous Solution. In preferred embodiments, the skilled artisan in view of the teachings herein and may be selected Suspension medium is bacteriostatic. accomplished without undue experimentation. In any event, 0083. As indicated above, the suspension media may the use of these and Substantially equivalent methods pro comprise any one of a number of different compounds vide for the formation of hollow porous aerodynamically including hydrocarbons, fluorocarbons or hydrocarbon/fluo light microspheres with particle diameters appropriate for rocarbon diblocks. In general, the contemplated hydrocar aerosol deposition into the lung. bons or highly fluorinated or perfluorinated compounds may 0080 Along with spray drying the perforated microstruc be linear, branched or cyclic, Saturated or unsaturated com tures of the present invention may be formed by lyophiliza pounds. Conventional structural derivatives of these fluoro tion. Those skilled in the art will appreciate that lyophiliza chemicals and hydrocarbons are also contemplated as being tion is a freeze-drying process in which water is Sublimed within the scope of the present invention. Selected embodi from the composition after it is frozen. The particular ments comprising these totally or partially fluorinated com advantage associated with the lyophilization process is that pounds may contain one or more hetero-atoms including biologicals and pharmaceuticals that are relatively unstable bromine or chlorine. Preferably, these fluorochemicals com in an aqueous Solution can be dried without elevated tem prise from 1 to 16 carbon atoms and include, but are not peratures (thereby eliminating the adverse thermal effects), limited to, linear, cyclic or polycyclic perfluoroaacanes, and then stored in a dry state where there are few stability bis(perfluoroalkyl)alkenes, perfluoroethers, perfluoroam problems. With respect to the instant invention such tech ines, perfluoroalkyl bromides and perfluoroalkyl chlorides niques are particularly compatible with the incorporation of such as dichlorooctane. Particularly preferred fluorinated peptides, proteins, genetic material and other natural and compounds for use in the Suspension medium may comprise synthetic macromolecules in the perforated microstructures perfluorooctyl bromide, C. F., Br (PFOB or perflubron), without compromising physiological activity. Methods for dichlorofluorooctane C. F. Cl, and the hydrofluoroalkane providing lyophilized particulates are known to those of skill perfluorooctyl ethane C. F. C. Hs (PFOE). In selected in the art and it would clearly not require undue experimen embodiments the Suspension medium will comprise a com tation to provide dispersion compatible microstructures in pound (particularly a fluorochemical) having a positive accordance with the teachings herein. Accordingly, to the spreading coefficient. Other useful preparations may com extent that lyophilization processes may be used to provide prise perfluorohexane or perfluoropentane as Suspension microstructures having the desired porosity and size they are media. conformance with the teachings herein and are expressly 0084 More generally, exemplary fluorochemicals which contemplated as being within the scope of the instant are contemplated for use in the present invention generally invention. include halogenated fluorochemicals (i.e. CFX, 0081 Besides the aforementioned techniques, the perfo XCFX, where n=2-10, X=Br, C1 or 1) and, in particular, rated microstructures of the present invention may also be 1-bromo-F-butane n-CFBr, 1-bromo-F-hexane formed using a double emulsion method. In the double (n-CFBr), 1-bromo-F-heptane (n-CFBr) 1,4-dibromo emulsion method the medicament is first dispersed in a F-butane and 1,6-dibromo-F-hexane. Other useful bromi polymer dissolved in an organic solvent (e.g. methylene nated fluorochemicals are disclosed in U.S. Pat. No. 3,975, chloride) by Sonication or homogenization. This primary 512 to Long, which is incorporated herein by reference. emulsions then stabilized by forming a multiple emulsion in Specific fluorochemicals having chloride substituetnts, such a continuous aqueous phase containing an emulsifier Such as as perfluorooctyl chloride (n-Cs F, Cl), 1,8-dichloro-F- polyvinylalcohol. Evaporation or extraction using conven heptane (n-CICFCI), 1,6-dichloro-F-hexane tional techniques and apparatus then removes the organic (n-CICFCI), and 1,4-dichloro-F-butane (n-CICFCI) are solvent. The resulting microspheres are washed, filtered and also preferred. dried prior to combining them with an appropriate Suspen 0085. Fluorocarbons, fluorocarbon-hydrocarbon com sion medium in accordance with the present invention. pounds and halogenated fluorochemicals containing other 0082) Regardless of how the microstructures or particles linkage groups. Such as esters, thioethers and amines are also are formed, the selected Suspension media used to provide Suitable for use as Suspension media in the present invention. the desired stabilized dispersion is preferably compatible For instance, compounds having the general formula, C with pulmonary administration. In general, the selected 1OCF2, or CF2 CH=CHC F2, (as for example suspension medium should be biocompatible (i.e. relatively CFCH=CHCF (F-44E), i-CFCH=CHCF non-toxic) and non-reactive with respect to the Suspended (F-i36E), and CFCH=CHCF (F-66E)) where n and m perforated microstructures comprising the bioactive agent. are the same or different and n and mare integers from about Preferred embodiments comprise suspension media selected 2 to about 12 are compatible with teachings herein. Useful from the group consisting of fluorochemicals, fluorocarbons fluorochemical-hydrocarbon diblock and triblock com (including those Substituted with other halogens), perfluo pounds include those with the general formulas CF rocarbons, fluorocarbon/hydrocarbon diblocks, hydrocar CnH2n, and C.F.C. Hall, where n=2-12; m-2-16 or bons, alcohols, ethers, or combinations thereof. It will be CH2—CF CH2, where p=1-12, m=1-12 and US 2007/0212405 A1 Sep. 13, 2007 n=2-12. Preferred compounds of this type include therapy. Moreover, more volatile compounds may be mixed CsF17C2H5. CoFis CoH21. CsF17CsH17, with lower vapor pressure components to provide Suspen CFCH=CHCH, and C8F, CH=CHC, H. Substi sion media having specified physical characteristics selected tuted ethers or polyethers (i.e. XC F OCF.X. to further improve stability or enhance the bioavailability of XCFOCFOCFX, where n and m=1-4, X= Br, C1 or l) and the dispersed bioactive agent. fluorochemical-hydrocarbon ether diblocks or triblocks (i.e. CFO CH2, where n=2-10; m=2-16 or CH2— 0089) Other embodiments of the present invention will O—CF O-CH2, where p=2-12, m=1-12 and n=2- comprise Suspension media that boil at selected tempera 12) may also used as well as CFO C. FOCHI, tures under ambient conditions (i.e. 1 atmosphere). For wherein n, m and p are from 1-12. Furthermore, depending example, preferred embodiments will comprise Suspension on the application, perfluoroalkylated ethers or polyethers media compounds that boil above 0°C., above 5°C., above 10°C., above 15° C., or above 20°C. In other embodiments, may be compatible with the claimed dispersions. the suspension media compound may boil at or above 25°C. 0.086 Polycyclic and cyclic fluorochemicals, such as or at or above 30°C. In yet other embodiments; the selected CFs (F-decalin or perfluorodecalin), perfluoroperhydro Suspension media compound may boil at or above human phenanthrene, perfluorotetramethylcyclohexane (AP-144) body temperature (i.e. 37° C), above 45° C., 55° C., 65° C., and perfluoro n-butyldecalin are also within the scope of the 75° C., 85° C. or above 100° C. invention. Additional useful fluorochemicals include perflu orinated amines, such as F-tripropylamine (“FTPA) and 0090 The stabilized suspensions or dispersions of the F-tributylamine (“FTBA). F-4-methyloctahydroquinoliz present invention may be prepared by dispersal of the microstructures in the selected Suspension medium, which ine (“FMOQ), F-N-methyl-decahydroisoquinoline may then be placed in a container or reservoir. In this regard, (“FMIQ), F-N-methyldecaliydroquinoline (“FHQ), F-N- the stabilized preparations of the present invention can be cyclohexylpyrrolidine (“FCHP) and F-2-butyltetrahydrofu made by simply combining the components in Sufficient ran (“FC-75” or “FC-77). Still other useful fluorinated compounds include perfluorophenanthrene, perfluorometh quantity to produce the final desired dispersion concentra yldecalin, peifuorodimethyletliylcyclohexane, perfluo tion. Although the microstructures readily disperse without rodimethyldecal in, perfluorodiethyldecal in, perfluororn mechanical energy, the application of mechanical energy to ethyladamantane, perfluorodimethyladamantane. Other aid in dispersion (e.g. with the aid of Sonication) is contem contemplated fluorochemicals having nonfluorine Substitu plated, particularly for the formation of stable emulsions or ents, such as, perfluorooctyl hydride, arid similar com reverse emulsions. Alternatively, the components may be pounds having different numbers of carbon atoms are also mixed by simple shaking or other type of agitation. The useful. Those skilled in the art will further appreciate that process is preferably carried out under anhydrous conditions other variously modified fluorochemicals are encompassed to obviate any adverse effects of moisture on Suspension within the broad definition of fluorochemical as used in the stability. Once formed, the dispersion has a reduced Suscep instant application and Suitable for use in the present inven tibility to flocculation and sedimentation. tion. As such, each of the foregoing compounds may be 0091. It will also be understood that other components used, alone or in combination with other compounds to form can be included in the pharmaceutical compositions of the the stabilized dispersions of the present invention. present invention. For example, osmotic agents, stabilizers, chelators, buffers, Viscosity modulators, salts, and Sugars can 0087 Yet other specific fluorocarbons, or classes of flu be added to fine tune the stabilized dispersions for maximum orinated compounds, that may be useful as Suspension life and ease of administration. Such components may be media include, but are not limited to, fluoroheptane, fluo added directly to the Suspension medium, ether phase of an rocycloheptane fluoromethylcycloheptane, fluorohexane, emulsion or associated with, or incorporated in, dispersed fluorocyclohexane, fluoropentane, fluorocyclopentane, fluo particles or perforated microstructures. Considerations such romethylcyclopentane, fluorodimethylcyclopentanes, fluo as sterility, isotonicity, and biocompatibility may govern the romethylcyclobutane, fluorodimethylcyclobutane, fluorotri use of conventional additives to the disclosed compositions. methylcyclobutane, fluoiobutane, fluorocyclobutane, The use of such agents will be understood to those of fluoropropane, fluoroethers, fluoropolyethers and fluorotri ordinary skill in the art and, the specific quantities, ratios, ethylamines. Such compounds are generally environmen and types of agents can be determined empirically without tally sound and are biologically non-reactive. undue experimentation. 0088 While any biocompatible fluid compound may be 0092. The stabilized dispersions of the invention may used in conjunction with the present invention, the selected also comprise one or more additives to further enhance Suspension medium will preferably have a vapor pressure stability or increase biocompatibility. For example, various less than about 5 atmospheres and more preferably less than Surfactants, co-solvents, osmotic agents, stabilizers, chela about 2 atmospheres. Unless otherwise specified, all vapor tors, buffers, viscosity modulators, solubility modifiers and pressures recited herein are measured at 25° C. In other salts can be associated with the perforated microstructure, embodiments, preferred Suspension media compounds will suspension medium, or both. The use of such additives will have vapor pressures on the order of about 5 torr to about be understood to those of ordinary skill in the art and, the 760 torr, with more preferable compounds having vapor specific quantities, ratios, and types of agents can be deter pressures on the order of from about 8 torr to about 600 torr, while still more preferable compounds will have vapor mined empirically without undue experimentation. pressures on the order of from about 10 torr to about 350 0093. The stabilized suspensions or dispersions of the torr. Such suspension media may be used in conjunction present invention may be prepared by dispersal of the with compressed air nebulizers, ultrasonic nebulizers or with microstructures in the selected Suspension medium that may mechanical atomizers to provide effective ventilation then be placed in a container or reservoir. In this regard, the US 2007/0212405 A1 Sep. 13, 2007 stabilized preparations of the present invention can be made cian. When dispersions comprising combinations of bioac by simply combining the components in Sufficient quantity tive agents are administered, the dose of each agent will to produce the final desired dispersion concentration. That generally be that employed for each agent when used alone. is, the components of the preparations may be combined to provide a respiratory blend. Although the microstructures 0097 Direct administration of bioactive compounds is readily disperse without mechanical energy, the application particularly effective in the treatment of pulmonary disor of mechanical energy (e.g. Sonication) to the respiratory ders especially where poor vascular circulation of diseased blend to mix the components or aid in their dispersion is portions of a lung reduces the effectiveness of intravenous contemplated. Alternatively, the components may be mixed drug delivery. Accordingly, stabilized dispersions adminis by simple shaking or other type of agitation. The process is tered to the lung may prove useful in the treatment and/or preferably carried out under anhydrous conditions to obviate diagnosis of disorders such as respiratory distress syndrome, any adverse effects of moisture on Suspension stability. Once acute respiratory distress syndrome, lung contusions, divers formed, the dispersion has a reduced susceptibility to floc lung, post traumatic respiratory distress, post Surgical culation and sedimentation. atelectasis, septic shock, multiple organ failure, Men 0094. It will be appreciated that conventional pharma delssohn's disease, obstructive lung disease, pneumonia, ceutical equipment and methodology may be used during pulmonary edema, impaired pulmonary circulation, cystic production of the disclosed dispersions. For example, com fibrosis and lung cancer. In this regard, the stabilized dis mercially available spray drying and mixing equipment may persions are preferably used in conjunction with partial be used to form the perforated microstructures and desired liquid ventilation or total liquid ventilation. Moreover, the Suspensions. Accordingly, it is submitted that the skilled present invention may further comprise introducing a thera artisan would have little trouble producing the pharmaceu peutically beneficial amount of a physiologically acceptable tical dispersions of the present invention on a commercial gas (such as nitric oxide or oxygen) into the pharmaceutical scale when in possession of the instant disclosure. microdispersion prior to, during or following administration. 0095. It will further be appreciated that the stabilized 0098. As discussed throughout the instant specification, preparations of the present invention may be advantageously the compositions of the present invention may be adminis Supplied to the physician or other health care professional, tered to the lung using a pulmonary delivery conduit. Those in a sterile, prepackaged or kit form. More particularly, the skilled in the art will appreciate the term “pulmonary formulations may be supplied as stable, preformed disper delivery conduit', as used herein, shall be construed in a sions ready for administration or, as separate ready to mix broad sense to comprise any device or apparatus, or com components. When provided in a ready to use form, the ponent thereof, that provides for the instillation or admin dispersions may be packaged in single use containers or istration of a liquid in the lungs. In this respect a pulmonary reservoirs (e.g. in glass vials comprising a few milliliters of delivery conduit or delivery conduit shall be held to mean the dispersion) or in multi-use containers or reservoirs. any bore, lumen, catheter, tube, conduit, Syringe, actuator, When provided as individual components (e.g., as powdered mouthpiece, endotracheal tube or bronchoscope that pro microspheres and as neat Suspension medium) the stabilized vides for the administration or instillation of the disclosed preparations may then be formed at any time prior to use by dispersions to at least a portion of the pulmonary air pas simply combining the contents of the containers as directed. sages of a patient in need thereof. It will be appreciated that For example, a small Volume of concentrated dispersion the delivery conduit may or may not be associated with a could be diluted in a larger volume of neat fluorocarbon liquid ventilator or gas ventilator. In particularly preferred prior to its use in liquid ventilation. Additionally, due to the embodiments the delivery conduit shall comprise an endot Superior stability of the disclosed preparations, the kits may racheal tube or bronchoscope. contain a number of ready to mix, or prepackaged disper 0099. Accordingly, liquid dose instillation preferably sions in a single use form so that the user can readily select involves the instillation of the perforated microstructures in or modify the therapeutic regimen for the particular indica a suitable Suspension medium to an intubated patient tion. In this regard, each of the containers may be fitted with through an endotracheal tube, or to a free-breathing patient a septum for direct removal of the dispersion or with via bronchoscope. Other embodiments comprise the admin appropriate tubing, cannulas, Luer fittings, etc. for associa istration of the disclosed dispersions directly into the throat. tion with a ventilator or endotracheal apparatus. It will also That is, the formulations of the present invention may be be appreciated that such kits may optionally include a “trickled into the lungs of the patient as a bolus using bronchoscope or endotracheal apparatus (or components standard tubing and/or a syringe: Here it must be empha thereof) for administration of the preparations. sized that the dispersions of the present invention may be 0096] Administration of bioactive agent may be indicated administered to ventilated (e.g. those connected to a for the treatment of mild, moderate or severe, acute or mechanical ventilator) or nonventilated, patients (e.g. those chronic symptoms or for prophylactic treatment. Moreover, undergoing spontaneous respiration). Accordingly, in pre the bioactive agent may be administered to treat local or ferred embodiments the methods and systems of the present systemic conditions or disorders. In this regard, one particu invention may comprise the use or inclusion of a mechanical larly preferred embodiment comprises the systemic admin ventilator. Further, the stabilized dispersions of the present istration (e.g. delivery to the systemic circulation of a patient invention may also be used as a lavage agent to remove via the pulmonary air passages) of a bioactive agent. It will debris in the lung, or for diagnostic lavage procedures. In further be appreciated that the precise dose administered will any case the introduction of liquids, particularly fluoro depend on the age and condition of the patient, the particular chemicals, into the lungs of a patient is well known and medicament used and the frequency of administration and could be accomplished by a skilled artisan in possession of will ultimately be at the discretion of the attendant physi the instant specification without undue experimentation. US 2007/0212405 A1 Sep. 13, 2007

0100. It will be understood that, in connection with the modynamically very favorable. By way of contrast, there is present invention, the disclosed dispersions are preferably no large driving force when the Surfactant is moving from administered directly to at least a portion of the pulmonary one aqueous medium to another. Accordingly, particularly air passages of a mammal. As used herein, the terms “direct preferred embodiments of the present invention comprise instillation' or "direct administration' shall be held to mean perforated microstructures associated with, or incorporating, the introduction of a stabilized dispersion into the lung natural or synthetic surfactants distributed in a fluorochei cavity of a mammal. That is, the dispersion will preferably nical Suspension medium. be administered through the trachea of a patient and into the lungs as a liquid. While the dispersions may be administered 0.104 While the stabilized dispersions may be adminis in the form of an aerosol or nebulized liquid, they will tered up to the functional residual capacity of the lungs of a preferably be introduced as a volume of a relatively free patient, it will be appreciated that selected embodiments will flowing liquid passing through a delivery conduit and into comprise the pulmonary administration of much smaller the pulmonary air passages. In this regard, the flow of the volumes (e.g. on the order of a milliliter or less). For dispersion may be gravity assisted or may be afforded by example, depending on the disorder to be treated, the induced pressure Such as through a pump or the compression volume administered may be on the order of 1, 3, 5, 10, 20, of a syringe plunger. In any case, the amount of dispersion 50, 100, 200 or 500 milliliters. In preferred embodiments the administered may be monitored by mechanical devices Such liquid volume is less than 0.25 or 0.5 percent FRC. For as flow meters or by visual inspection. particularly preferred embodiments, the liquid volume is 0.1 0101. It will further be appreciated that, liquid ventilation percent FRC or less. With respect to the administration of (partial or total) involves the introduction of a respiratory relatively low volumes of stabilized dispersions it will be promoter (typically a fluorochemical) to the lung for the appreciated that the wettability and spreading characteristics promotion of physiological gas exchange. For partial liquid of the Suspension media (particularly fluorochemicals) will ventilation, the patient is preferably ventilated using a facilitate the even distribution of the bioactive agent in the mechanical ventilator following pulmonary introduction of lung. However, in other embodiments it may be preferable the liquid. In accordance with the teachings herein the respiratory promoter may comprise a stabilized dispersion. to administer the Suspensions a volumes of greater than 0.5. For example, perforated microparticles comprising penicil 0.75 or 0.9 percent FRC. In any event, LDI treatment as lin may be suspended in perfluorooctyl bromide to provide disclosed herein represents a new alternative for critically ill a stabilized dispersion that could be used for liquid venti patients on mechanical ventilators, and opens the door for lation. This dispersion could then be administered, at any treatment of less ill patients with bronchoscopic adminis Volume up to functional residual capacity (FRC), to the lung tration. of a patient as described in U.S. Pat. Nos. 5.562,608, 0105 While the stabilized dispersions of the present 5,437,272, 5,490,498, 5,667,809, 5,770,585 and 5,540,225 invention are particularly suitable for the pulmonary admin each of which is incorporated herein by reference. istration of bioactive agents, they may also be used for the 0102 Alternatively, a concentrated, but relatively stable, localized or systemic administration of compounds to any dispersion could be packaged in a single dose configuration location of the body. Accordingly, it should be emphasized having a total volume on the order of a few milliliters or less. that, in preferred embodiments, the formulations may be It will be appreciated that the relatively small volume could administered using a number of different routes including, be administered directly to the lung. However, in preferred but not limited to, the gastrointestinal tract, the respiratory embodiments this concentrated dispersion could be mixed tract, topically, intramuscularly, intraperitoneally, nasally, with a larger Volume of neat respiratory promoter (which vaginally, rectally, aurally, orally or ocular. More generally, may be the same or different as the Suspension medium) the stabilized dispersions of the present invention may be prior to introduction to the lung. In still other embodiments used to deliver agents topically or by administration to a the concentrated dispersion could be administered directly to the lung of a patient already containing respiratory promoter. non-pulmonary body cavity. In preferred embodiments the That is, for intubated patients undergoing partial liquid body cavity is selected from the group consisting of the ventilation, the bioactive agent Suspension may be top peritoneum, sinus cavity, rectum, urethra, gastrointestinal loaded onto an existing Volume of a fluorochemical. In each tract, nasal cavity, vagina, auditory meatus, oral cavity, of these cases, the respiratory promoter and/or Suspension buccal pouch and pleura. Among other indications, stabi medium will provide for the efficient dispersal and deposi lized dispersions comprising the appropriate bioactive agent, tion of the bioactive perforated microspheres on the lung (e.g. an antibiotic or an anti-inflammatory), may be used to membrane. treat infections of the eye, sinusitis, infections of the audi tory tract and even infections or disorders of the gastrointes 0103 More specifically, by providing for the administra tinal tract. With respect to the latter, the dispersions of the tion of bioactive agents in what can be a relatively anhy present invention may be used to selectively deliver phar drous environment, i.e. in a fluorochemical, physiological maceutical compounds to the lining of the stomach for the uptake of the agent may be dramatically increased. This is treatment of H. pylori infections or other ulcer related particularly true of lung Surfactants such as phospholipids. disorders. As discussed more fully in Example XIV below the adsorp tion time for Surfactant is exponentially decreased when it is 0106 The foregoing description will be more fully under brought into contact with a wetted Surface (lung membrane) stood with reference to the following Examples. Such by a fluorochemical as opposed to an aqueous solution. This Examples, are, however, merely representative of preferred is because adsorption of the Surfactant from an anhydrous methods of practicing the present invention and should not Suspension medium into an aqueous environment is ther be read as limiting the scope of the invention. US 2007/0212405 A1 Sep. 13, 2007

EXAMPLE I the incorporation of additional blowing agent. In this regard, both the hollow nature and wall thickness of the resulting Preparation of Hollow Porous Particles of perforated microstructures appeared to be largely dependent Gentamicin Sulfate by Spray-Drying on the concentration of the selected blowing agent. That is, 0107 40 to 60 ml of the following solutions were pre the hollow nature of the preparation appeared to increase pared for spray drying: 50% w/w hydrogenated phosphati and the thickness of the particle walls appeared to decrease dylcholine, E-100-3 (Lipoid KG, Ludwigshafen, Germany) as the PFC/PC ratio increased. Substantially non-porous, 50% w/w gentamicin sulfate (Amresco, Solon, Ohio) Per relatively solid structures were obtained from formulations fluorooctylbromide, Perflubron (NMK, Japan) Deionized containing little or no fluorocarbon blowing agent. Con Water versely, the perforated microstructures produced using a 0108 Perforated microstructures comprising gentamicin relatively high PFC/PC ratio of approximately 45 proved to Sulfate were prepared by a spray drying technique using a be extremely hollow with a relatively thin wall ranging from B-191 Mini Spray-Drier (Bichi, Flawil, Switzerland) under about 43.5 to 261 nm. In keeping with the teachings herein, the following conditions: aspiration: 100%, inlet tempera both types of particles are compatible for use in the present ture: 85°C.; outlet temperature: 61° C.; feed pump: 10%; N. invention. flow: 2,800 L/hr. Variations in powder porosity were exam ined as a function of the blowing agent concentration. EXAMPLE III 0109 Fluorocarbon-in-water emulsions of perfluorooctyl bromide containing a 1:1 w/w ratio of phosphatidylcholine Preparation of Hollow Porous Particles of Albuterol (PC), and gentamicin Sulfate were prepared varying only the Sulfate by Spray-Drying PFC/PC ratio. 1.3 grains of hydrogenated egg phosphatidyl choline was dispersed in 25 mL deionized water using an 0112 Hollow porous albuterol sulfate particles were pre Ultra-Turrax mixer (model T-25) at 8000 rpm for 2 to 5 pared by a spray-drying technique with a B-191 Mini minutes (T=60-70° C.). A range from 0 to 40 grams of Spray-Drier (Bichi, Flawil, Switzerland) under the follow perflubron was added dropwise during mixing (T=60-70° ing spray conditions: aspiration: 100%, inlet temperature: C.). After addition was complete, the fluorocarbon-in-water 85° C.; outlet temperature: 61° C.; feed pump: 10%; N. emulsion was mixed for an additional period of not less than flow: 2,800 L/hr. The feed solution was prepared by mixing 4 minutes. The resulting coarse emulsions were then homog two solutions A and B immediately prior to spray drying. enized under high pressure with an Avestin (Ottawa, Canada) homogenizer at 15,000 psi for 5 passes. Gentamicin 0113 Solution A: 20 g of water was used to dissolve 1 g sulfate was dissolved in approximately 4 to 5 mL deionized of albuterol sulfate (Accurate Chemical, Westbury, N.Y.) water and subsequently mixed with the perflubron emulsion and 0.021 g of poloxamer 188 NF grade (BASF, Mount immediately prior to the spray dry process. The gentamicin Olive, N.J.). powders were then obtained by spray drying using the conditions described above. A free flowing pale yellow 0114 Solution B: A fluorocarbon-in-water emulsion sta powder was obtained for all perflubron containing formu bilized by phospholipid was prepared in the following lations. The yield for each of the various formulations manner. The phospholipid, 1 g EPC-100-3 (Lipoid KG, ranged from 35% to 60%. Ludwigshafen, Germany), was homogenized in 150 g of hot deionized water (T=50 to 60° C.) using an Ultra-Turrax EXAMPLE II mixer (model T-25) at 8000 rpm for 2 to 5 minutes (T60-70° C.). 25 g of perfluorooctyl bromide (Atochern, Paris, Morphology of Gentamicin Sulfate Spray-Dried France) was added dropwise during mixing. After the fluo Powders rocarbon was added, the emulsion was mixed for a period of not less than 4 minutes. The resulting coarse emulsion was 0110. A strong dependence of the powder morphology, then passed through a high pressure homogenizer (Avestin, degree of porosity, and production yield was observed as a Ottawa, Canada) at 18,000 psi for 5 passes. function of the PFC/PC ratio by scanning electron micros copy (SEM), of the samples obtained in Example I. In the 0115 Solutions A and B were combined and fed into the micrographs, the porosity and Surface roughness was found spray-dryer under the conditions described above. A free to be highly dependent on the concentration of the blowing flowing white powder was collected at the cyclone separator. agent, where the Surface roughness, number and size of the The hollow porous albuterol sulfate particles had a volume pores increased with increasing PFC/PC ratios. For example, weighted mean aerodynamic diameter of 1.18t1.42 Lum as the formulation devoid of perfluorooctyl bromide produced determined by a time-of-flight analytical method (Aerosizer, microstructures that appeared to be highly agglomerated and readily adhered to the surface of the glass vial. Similarly, Amherst Process Instruments, Amherst, Mass.). Scanning Smooth, spherically shaped microparticles were obtained electron microscopy (SEM) analysis showed the powders to when relatively little (PFC/PC ratio=1.1 or 2.2) blowing be spherical and highly porous. The tap density of the agent was used. However, as the PFC/PC ratio increased, the powder was determined to be less than 0.1 g/cm. particles showed dramatic increases in porosity and Surface 0.116) This foregoing example serves to illustrate the roughness. inherent diversity of the present invention as a drug delivery 0111. As revealed by transmission electron microscopy platform capable of effectively incorporating any one of a (TEM) cross sections of the particles revealed that the number of pharmaceutical agents. The principle is further hollow nature of the microstructures was also enhanced by illustrated in the next example. US 2007/0212405 A1 Sep. 13, 2007 17

EXAMPLE IV EXAMPLE VI Formation of Porous Particulate Microstructures Preparation of Hollow Porous Particles of BDP by Comprising Mixture of Long-Chain/Short-Chain Spray-Drying Phospholipids and Albuterol Sulfate 0122) Perforated microstructures comprising beclom 0117. A dispersion for spray-drying was prepared as ethasone dipropionate (BDP) particles were prepared by a described in Example III above, with the difference that 1 g spray-drying technique with a B-191 Mini Spray-Drier of DSPC was dispersed with 100 mg of a short-chain (Büchi, Flawil, Switzerland) under the following spray phospholipid, dioctylphosphatidylcholine (DOPC) (Avanti conditions: aspiration: 100%, inlet temperature: 85° C.; Polar Lipids, Alabaster, Ala.). The composition of the spray outlet temperature: 61° C.; feed pump: 10%: N, flow: 2,800 feed is shown in Table II immediately below. The resulting L/hr. The feed stock was prepared by mixing 0.11 g of yield was 50%. lactose with a fluorocarbon-in-water emulsion immediately prior to spray drying. The emulsion was prepared by the TABLE II technique described below. Composition of the Spray Feed 0123 74 mg of BDP (Sigma, Chemical Co., St. Louis, Mo.), 0.5 g of EPC-100-3 (Lipoid KG, Ludwigshafen, Component Quantity Germany), 15 mg Sodium oleate (Sigma); and 7 mg of Disteroylphosphatidylcholine (DSPC) 1 g poloxamer 188 (BASF, Mount Olive, N.J.) were dissolved in Dioctanoylphosphatidylcholine (DOPC) 0.1 g AIbuterol Sulfate 1 g 2 ml of hot methanol. The methanol was then evaporated to Perfluorohexane 1 g obtain a thin film of the phospholipid/steroid mixture. The Water 60 g phospholipid/steroid mixture was then dispersed in 64 g of hot deionized water (T=50 to 60° C.) using an Ultra-Turrax mixer (model T-25) at 8000 rpm for 2 to 5 minutes (T=60 EXAMPLE V 70° C.). 8 g of perflubron (Atochem, Paris, France) was added dropwise during mixing. After the addition was Preparation of Hollow Porous Particles of complete, the emulsion was mixed for an additional period Cromolyn Sodium by Spray-Drying of not less than 4 minutes. The resulting coarse emulsion 0118 Perforated microstructures comprising cromolyn was then passed through a high pressure homogenizer Sodium were prepared by a spray-drying technique with a (Avestin, Ottawa, Canada) at 18,000 psi for 5 passes. This B-191 Mini Spray-Drier (Bichi, Flawil, Switzerland) under emulsion was then used to form the feed Stock that was spray the following spray conditions: aspiration: 100%, inlet tem dried as described above. A free flowing white powder was perature: 85°C.; outlet temperature: 610° C.; feed pump: collected at the cyclone separator. The hollow porous BDP 10%; N flow: 2,800 L/hr. The feed solution was prepared by particles had a tap density of less than 0.1 g/cm. mixing two solutions A and B immediately prior to spray drying. EXAMPLE VII 0119) Solution A: 20 g of water was used to dissolve 1 g Preparation of Hollow Porous Particles of TAA by of cromolyn sodium (Sigma Chemical Co., St. Louis, Mo.) Spray-Drying and 0.021 g of poloxamer 188 NF grade (BASF, Mount Olive, N.J.). 0.124 Perforated microstructures comprising triamcino 0120 Solution B: A fluorocarbon-in-water emulsion sta lone acetonide (TAA) particles were prepared by a spray bilized by phospholipid was prepared in the following drying technique with a B-191 Mini Spray-Drier (Bichi, manner. The phospholipid, 1 g EPC-100-3 (Lipoid KG, Flawil, Switzerland) under the following spray conditions: Ludwigshafen, Germany), was homogenized in 1 S0 g of hot aspiration: 100%, inlet temperature: 85°C.; outlet tempera ture: 61° C.; feed pump: 10%: N, flow: 2,800 L/hr. The feed deionized water (T=50 to 60° C.) using an Ultra-Turrax stock was prepared by mixing 0.57 g of lactose with a mixer (model T-25) at 8000 rpm for 2 to 5 minutes (T=60 fluorocarbon-in-water emulsion immediately prior to spray 70° C.). 27 g of perfluorodecalin (Air Products, Allentown, drying. The emulsion was prepared by the technique Pa.) was added dropwise during mixing. After the fluoro described below. 100 mg of TAA (Sigma, Chemical Co., St. carbon was added, the emulsion was mixed for at least 4 Louis, Mo.), 0.56 g of EPC-100-3 (Lipoid KG, Ludwig minutes. The resulting coarse emulsion was then passed shafen, Germany), 25 mg Sodium oleate (Sigma), and 13 mg through a high pressure homogenizer (Avestin, Ottawa, of poloxamer 188 (BASF, Mount Olive, N.J.) were dis Canada) at 18,000 psi for 5 passes. solved in 2 ml of hot methanol. The methanol was then 0121 Solutions A and B were combined and fed into the evaporated to obtain a thin film of the phospholipid/steroid spray dryer under the conditions described above. A free mixture. The phospholipid/steroid mixture was then dis flowing pale yellow powder was collected at the cyclone persed in 64 g of hot deionized water (T=50 to 60°C.) using separator. The hollow porous cromolyn Sodium particles had an Ultra-Turrax mixer (model T-25) at 8000 rpm for 2 to 5 a volume-weighted mean aerodynamic diameter of minutes (T=60 to 70° C.). 8g of perflubron (Atochem, Paris, 1.23+1.31 um as determined by a time-of-flight analytical France) was added dropwise during mixing. After the fluo method (Aerosizer, Amherst Process Instruments, Amherst, rocarbon was added, the emulsion was mixed for at least 4 Mass.). Scanning electron microscopy (SEM) analysis minutes. The resulting coarse emulsion was then passed showed the powders to be both hollow and porous. The tap through a high pressure homogenizer (Avestin, Ottawa, density of the powder was determined to be less than 0.1 Canada) at 18,000 psi for 5 passes. This emulsion was then g/cm. used to form the feed stock that was spray dried as described US 2007/0212405 A1 Sep. 13, 2007 above. A free flowing white powder was collected at the 0132) Solution 2: 0.45% w/v Poloxamer 188 (BASF, cyclone separator. The hollow porous TAA particles had a Mount Olive, N.J.) 1.35% w/v Hydrogenated egg phosphati tap density of less than 0.1 g/cm. dylcholine, EPC-3 (Lipoid KG, Ludwigshafen, Germany) 0.133 The ingredients of solution 1 were dissolved in EXAMPLE VIII warm water using a stir plate. The Surfactants in solution 2 Preparation of Hollow Porous Particles of DNase I were dispersed in water using a high shear mixer. The by Spray-Drying Solutions were combined following emulsification and satu rated with nitrogen prior to spray drying. 0125 Hollow porous DNase I particles were prepared by a spray drying technique with a B-191 Mini Spray-Drier 0.134. The resulting dry, free flowing, hollow, spherical (Bichi, Flawil, Switzerland) under the following conditions: product had a mean particle diameter of 2.6+1.5 lum. The aspiration: 100%, inlet temperature: 80° C.; outlet tempera particles, which may be used for the replacement or aug ture: 61° C.; feed pump: 10%: N, flow: 2,800 L/hr. The feed mentation of lung Surfactant, were spherical and porous as was prepared by mixing two solutions A and B immediately determined by SEM. prior to spray drying. 0.135 This example illustrates the point that a wide variety of blowing agents (here nitrogen) may be used to 0126 Solution A: 20 g of water was used to dissolve 0.5 provide microstructures exhibiting desired morphology. gr of human pancreas DNase I (Calbiochem, San Diego Indeed, one of the primary advantages of the present inven Calif.) and 0.012 g of poloxamer 188 NF grade (BASF, tion is the ability to alter formation conditions so as to Mount Olive, N.J.). preserve biological activity (i.e. with proteins or lung Sur 0127 Solution B: A fluorocarbon-in-water emulsion sta factant) or produce microstructures having selected porosity. bilized by phospholipid was prepared in the following way. The phospholipid, 0.52g EPC-100-3 (Lipoid KG, Ludwig EXAMPLE X shafen, Germany), was homogenized in 87 g of hot deion ized water (T=50 to 60° C.) using an Ultra-Turrax mixer Preparation of Perforated Microstructure Powder (model T-25) at 8000 rpm for 2 to 5 minutes (T=60-70° C.). Containing Ampicillin 13 g of perflubron (Atochem, Paris, France) was added 0.136 The following materials were obtained and used to dropwise during mixing. After the fluorocarbon was added, provide a feed stock: 20% w/w Ampicillin, Biotech grade the emulsion was mixed for at least 4 minutes. The resulting (Fisher Scientific, Pittsburgh, Pa.) 14.38% w/w Hydroxy coarse emulsion was then passed through a high pressure ethyl starch (Ajinomoto, Japan) 65.62% w/w Dipalmi homogenizer (Avestin, Ottawa, Canada) at 18,000 psi for 5 toylphosphatidylcholine (Genzyme, Cambridge, Mass.) Per passes. fluorohexane (3M, St. Paul, Minn.) Deionized water 0128 Solutions A and B were combined and fed into the 0.137 Hydroxyethyl starch, (HES: 0.9 g), and dipalmi spray dryer under the conditions described above. A free toylphosphatidylcholine (DPPC; 4.11 g) were dispersed in flowing pale yellow powder was collected at the cyclone 75 ml deionized water using an Ultra-Turrax mixer (model separator. The hollow porous DNase I particles had a T-25) at 10,000 rpm for approximately 2 minutes (T=45-50. volume-weighted mean aerodynamic diameter of 1.29+1.40 C.). The resulting DPPC/HES dispersion was chilled in an um as determined by a time-of-flight analytical method ice bath. Ampicillin (1.25 g) was added and allowed to mix (Aerosizer, Amherst Process Instruments, Amherst, Mass.). for 1 minute (T=5-10. C.). Perfluorohexane (PFH, 4.11 g) Scanning electron microscopy (SEM) analysis showed the was then added dropwise during mixing (T=5-10°C.). After powders to be both hollow and porous. The tap density of the the addition was complete, the PFH-in-water emulsion was powder was determined to be 3 less than 0.1 g/cm. mixed on the Ultra-Turrax for a total of not less than 4 0129. The foregoing example further illustrates the minutes. extraordinary compatibility of the present invention with a 0.138 A perforated microstructure powder comprising variety of bioactive agents. That is, in addition to relatively ampicillin was obtained by spray-drying (Bichi, 191 Mini Small hardy compounds such as steroids, the preparations of Spray Dryer, Switzerland) the amplicillin containing emul the present invention may be formulated to effectively sion at a rate of 5.5 ml/min. The inlet and outlet temperatures incorporate larger, fragile molecules Such as peptides, pro of the spray dryer were 90° C. and 55° C. respectively. The teins and genetic material. nebulization air and aspiration flows were 1,800 L/hr and 100% respectively. A free flowing white powder comprising EXAMPLE IX porous microspheres was obtained. Preparation of Hollow Porous Powder by Spray Drying a Gas-in-Water Emulsion EXAMPLE XI 0130. The following solutions were prepared with water Preparation of Perforated Microstructure Powder for injection: Containing Insulin 0131 Solution 1: 3.9% w/v M-HES hydroxyethylstarch 0.139. The following materials were obtained and used to (Ajinomoto, Tokyo, Japan) 3.25% w/v Sodium chloride provide a feed stock: 0.004.5% w/w Human Insulin, (Cal (Mallinckrodt, St. Louis, Mo.) 2.83% w/v Sodium phos biochem, San Diego, Calif.) 17.96% w/w Hydroxyethyl phate, dibasic (Mallinckrodt, St. Louis, Mo.) 0.42% w/v. starch (Ajinomoto, Japan) 82.04% w/w Dipalmitoylphos Sodium phosphate, monobasic (Mallinckrodt, St. Louis, phatidylcholine (Genzyme, Cambridge, Mass.) Perfluoro Mo.) hexane (3M, St. Paul, Minn.) Deionized water US 2007/0212405 A1 Sep. 13, 2007

0140 Hydroxyethyl starch, (HES; 1.35 g) and dipalmi microshells were dissolved in normal saline at a concentra toylphosphatidylcholine (DPPC; 6.16 g) were dispersed in tion of 10 mg/ml and allowed to incubate for 15 minutes at 100 ml deionized water using an Ultra-Turrax mixer (model 37° C. Prior to analysis, the surfactant test solutions were T-25) at 10,000 rpm for approximately 2 minutes (T=45-50° vigorously shaken using a Vortex mixer for 30 seconds. The C.). The resulting DPPC/HES dispersion was then chilled in samples were analyzed for their surface properties using the an ice bath. Insulin (3.4 mg) was added and allowed to mix Pulsating Bubble Surfactometer at 37° C. (model EC-PBS for 1 minute (T=5-10° C.). Perfluorohexane (PFH, 6.16 g) B, Electronics, Amherst, N.Y.) according to the manufac was then added dropwise during mixing (T=5-10°C.). After turers instructions. Surfactant solutions were allowed to the addition was complete, the resulting PFH-in-water emul adsorb at minimum bubble diameter for 10 seconds, and sion was mixed with the Ultra-Turrax) for a total of not less bubble cycling was performed in the automatic mode (20 than 4 minutes. The insulin microstructure powder was cycles/minute). For each experiment, measurements were obtained using a Bichi model 191 mini spray dryer (Bichi, taken for approximately the first 10 cycles, then again at 2, Switzerland). The insulin containing emulsion was fed at a 4, and 6 minutes. rate of 5.5 ml/min. The inlet and outlet temperatures of the 0144. The main difference observed between the neat and spray dryer were 80° C. and 45° C. respectively. The spray dried Surfactant Suspensions is the rate at which they nebulization air and aspiration flows were 1,800 L/hr and adsorb to the bubble surface and thus lower the tension. The 100% respectively. A free flowing, white powder comprising spray-dried materials required 6 cycles to achieve low porous microspheres was obtained. Surface tension as compared with one cycle for the Alveofact sample. However, the magnitude of the tension at maximum, EXAMPLE XII and minimum bubble diameter were found to be approxi Preparation of Fluorescent-Labeled Perforated mately the same. Microstructure Powder via Spray Drying 0145 For the Alveofact dispersion, the tension decreased from 32 mN/m at maximum diameter to 4 mN/m at mini 0141. The following materials were obtained and used to mum in the first cycle. With further pulsation, a steady state manufacture feed stock: 0.2% w/w Nitrobenzoyldiol Phos oscillation was reached with a maximum tension Ys33 phatidylcholine (Avanti Polar Lipids, Alabaster, Ala.) 17.6% mN/m and a minimum tension Yis0 to 1 mN/m. For the w/w Hydroxyethyl starch (Ajinomoto, Japan) 82.2% w/w spray-dried lung microshell dispersion, the tension Dipalmitoylphosphatidylcholine (Genzyme, Cambridge, decreased from 36 mN/m at maximum diameter to 16 mN/m Mass.) Perfluorohexane (3M, St. Paul, Minn.) Deionized at minimum in the first cycle. By the sixth pulsation, Y, Water and Y were respectively 36 and 2 mN/m. Both the neat 0142. Dipalmitoylphosphatidylcholine (DPPC; 1 g) and Alveofact and the spray-dried lung Surfactant perforated nitrobenzoyldiol phosphatidylcholine (NBD-PC; 10 mg) microstructures satisfy the maximum and minimum surface were dissolved in 4 ml chloroform. The chloroform was then tension requirements for physiologically effective lung Sur removed using a Savant Speed VacTM (Model SC 200). factants as outlined by Notter; R. H. Notter, in Surfactant Hydroxyethyl starch, (RES: 0.9 g), dipalmitoylphosphati Replacement Therapy, (Eds: D. H. Shapiro, and R. H. dyl-choline (DPPC; 3.19 g) and 75 ml deionized water were Notter) Alan R. Liss, New York, 1989 these values should then added to the DPPC/NBD-PC thin film. The Surfactants range from 35 to about 5 mN/m, respectively. This example and Starch were then dispersed in the aqueous phase using an illustrates that, the compositions and methods of the present Ultra-Turrax mixer (model T-25) at 10,000 rpm for approxi invention are particularly useful for the replacement or mately 2 minutes (T=45-50° C.). The resulting NBD-PC/ augmentation of lung Surfactant in patients. DPPC/HES dispersion was chilled in an ice bath. Perfluo rohexane (PFH, 4.11 g ) was then added dropwise during EXAMPLE XIV mixing (T=5-10° C.). After the addition was complete, the resulting PFH-in-water emulsion was mixed on the Ultra Rapid Spreading of Spray-Dried Microshells in Turrax for an additional time of not less than 4 minutes. The PFCS fluorescently labeled microshell powder was obtained by spray drying (Bichi, 191 Mini Spray Dryer, Switzerland). 0146 Stabilized dispersions formed according to the The NBD-PC/DPPC/HES containing emulsion was fed at a present invention provide for enhanced Surfactant spreading rate of 5.5 ml/min. The inlet and outlet temperatures of the at the pulmonary air/water interface. In this regard, the spray dryer were 100° C. and 65° C. respectively. The equilibrium Surface tension of dimyristoylphosphatidylcho nebulization air and aspiration flows were 1,800 L/hr and line is ca. 22 mN/m. Aqueous based liposomes are adsorbed 100% respectively. A free flowing, yellow powder compris very slowly at the air/water interface as evidenced by the fact that, after 1800 seconds, the surface tension of an ing perforated microstructures was obtained. aqueous solution has not been significantly reduced. The slow adsorption for liposomes is due to the slow molecular EXAMPLE XIII diffusion of DMPC through the water phase. Surprisingly, Effect of Spray Drying on the In-Vitro Activity of adsorption of DMPC suspended in perflubron (PFOB) in the Lung Surfactant form of dry perforated microstructures is very fast, reducing the surface tension to equilibrium values within a few 0143. The activity of a spray dried lung surfactant prepa seconds. This rapid spreading and reduction of Surface ration to lower the surface tension of a pulsating bubble was tension is indicative of what would occur upon contacting compared with the neat lung Surfactant preparation. Bovine the perforated microstructures with a wetted pulmonary derived lung surfactant, Alveofact (Thomae, Biberach, Ger membrane. More specifically, the present example demon many) and spray-dried lung Surfactant containing strates that the disclosed stabilized dispersions provide for US 2007/0212405 A1 Sep. 13, 2007 20 the effective delivery of lung surfactants, and drugs to the with 100% of untreated control animals within 4 days of lung by liquid dose instillation. inoculation. Animals receiving 10 mg of amplicillin intra muscularly one day after inoculation exhibited improved EXAMPLE XV survival with 27% of the animals surviving to 10 days. Animals receiving 10 mg of amplicillin (prepared according Pharmacokinetics for Insulin and Glucose to Example X) in 10 ml of perflubron via LDI administration Following Administration via LDI vs. IM exhibited a survival of 87%. These results indicate that local 0147 The insulin formulation described in Example XI antibiotic treatment with the hollow porous microspheres of was administered via liquid dose instillation (0.86 IU in 4.5 the present invention, is extremely efficient in reducing the ml/kg of perflubron) and intramuscular (IM) to fasting mortality associated with life-threatening bacterial infec rabbits. In the case of LDI administration, rabbits were tions. anesthetized, intubated, placed on a respirator, and their lungs were instilled with ca. 4.5 ml/kg of perflubron. The EXAMPLE XVII hollow porous microsphere formulation of insulin was then top-loaded in a minimal perflubron Volume onto the existing Ampicillin Concentrations in the Lung and Serum perflubron in the lung, at a dose of 0.86 IU/kg. Control Following IM and LDI Administration animals were injected IM with a similar dose of insulin 0.150 Ampicillin concentrations in lung tissue and serum (Humulin R). Plasma levels of insulin were determined by were measured for the two treatment groups in Example XV a radioimmunoassay method, and the decrease in serum by a bioassay method. In this method, 60 ul of lung tissue glucose levels were also determined. The results are shown homogenate, or serum obtained from the rats at various in Tables III and IV. Extremely fast uptake of insulin into the points after dosing is placed on a sterile disk. The disk is systemic circulation was observerd following LDI adminis then placed on an agar plate covered with S. pneumoniae and tration. The relative bioavailability was found to be 53% incubated for 24 hr. Levels of antibiotic high enough to Little differences were noted in glucose modulation between inhibit growth of S. pneumoniae resulted in Zones of growth the IM and LDI groups. These results show the utility of LDI inhibition around the disk. The no-growth Zones were quan administration in the systemic delivery of bioactive agents. titated, and concentrations of antibiotic were calculated based on a standard curve. TABLE III 0151. The results for the IM and LDI groups are shown Insulin Pharmacokinetics following in Table V. Ampicillin has a short half-life in serum as noted LDI or IM administration to rabbits by the fact that ampicillin levels are undetectable following IM administration after only 2 hours. Following LDI admin Cmax Tmax AUC BIM istration, the serum levels persisted for at least 4 hours, Delivery Mode (IU/ml) (min.) (IU min/ml) (%) indicating a Sustained release of amplicillin into the blood. IM 11O.S 60 2O770 1OO Similarly, the local lung concentrations were 250 times LDI (4.5 ml/kg) 210.4 15 11100 53 higher with LDI delivery and persisted for several days. These results indicate that large local antibiotic concentra tions can be achieved at the site of the infection, without 0148 correspondingly high serum levels, following LDI admin istration. Moreover, unlike intramuscular administration, the TABLE IV higher concentrations provided by liquid dose instillation Serum glucose levels (mg/dl) following also persisted for several days following administration. LDI or IM administration to rabbits Such persistence could significally reduce dosing require mentS. Time (min.) IM LDI O 1842 175.7 TABLE V 5 253.6 218.8 10 256.0 211.7 Ampicillin pharmacokinetics in rat lung: 15 216.8 1982 effect of mode of administration. 30 1682 143.3 60 82.O 83.2 Time (hr) IM serum IM lung LDI serum LDI lung 90 48.2 38.2 120 18.0 31.2 1 1S.O 2.2 15.8 SO1.2 150 29.4 31.7 2 1.3 1.2 2.0 125.9 18O 28.8 33.4 3 O O 1.3 125.9 240 29.4 49.2 4 O O 2.5 SO.1 360 115.8 8 O O O 15.8 24 O O O 1O.O 48 O O O 3.0 72 O O O 2.O EXAMPLE XVI

Reduction in Rat Mortality Following Liquid Dose EXAMPLE XVIII Instillation of Antibiotics 0149 Male Wistar rats (ca 500 g) were inoculated Gentamicin Biodistribution in Rabbit Lung intratracheally with 10 colony forming units of Streptococ 0152 Comparison of biodistribution in New Zealand cus pneumoniae. The model is an acute pneumonia model white rabbits at one hour post-administration of 5 mg/kg US 2007/0212405 A1 Sep. 13, 2007 gentamicin by either IM or LDI methods was performed. 9. A dispersion according to claim 1 wherein the perme The gentamicin was administered in an LDI Volume of only able microstructures have a mean density selected to provide 1.8 ml/kg. individual lobes of the lungs were collected and a density differential with that of the suspension medium of analyzed quantitatively for gentamicin by an immunoassay less than 0.6 g/cm. method. The results are detailed in Table VI. The lung 10. A dispersion according to claim 1 wherein the Sus gentamicin concentrations were ca. 2 orders of magnitude pension medium comprises a fluorochemical. higher following local administration (LDI) than for IM 11. A dispersion according to claim 1 wherein the bioac administration. Excellent biodistribution across the lung tive agent comprises one or more of antiallergics, bronchodi lobes was observed following either IM or LDI administra lators, pulmonary lung Surfactants, analgesics, antibiotics, tion. leukotriene inhibitors or antagonists, antihistamines, anti inflammatories, antineoplastics, anticholinergics, anesthet TABLE VI ics, anti-tuberculars, imaging agents, cardiovascular agents, Biodistribution of Gentamicin (g gentamicing tissue) enzymes, steroids, genetic material, viral vectors, antisense in Rabbit Lungs Following LDI and IM Administration agents, proteins, peptides or combinations thereof. Administration Right Right Right Left Left 12. A dispersion according to claim 1 wherein the bioac Mode Upper Mid Lower Upper Lower tive agent is gentamicin. 13. A dispersion according to claim 1 wherein the per IM S.O 6.O 6.4 6.7 6.1 LDI 68O.S S64.3 646.7 206.3 412.9 meable microstructures have a mean diameter of 1-30 Lum. 14. A dispersion for the pulmonary delivery of a bioactive agent to a patient, the dispersion comprising: 0153. Those skilled in the art will further appreciate that (a) a plurality of permeable microstructures, the perme the present invention may be embodied in other specific able microstructures comprising at least one of a phos forms without departing from the spirit or central attributes pholipid, nonionic detergent, nonionic block copoly thereof In that the foregoing description of the present mer, ionic Surfactant, biocompatible fluorinated invention discloses only exemplary embodiments thereof, it Surfactant or combinations thereof; is to be understood that, other variations are contemplated as being within the scope of the present invention. Accordingly, (b) at least one bioactive agent; and the present invention is not limited to the particular embodi ments that have been described in detail herein. Rather, (c) a suspension medium that permeates into the perme reference should be made to the appended claims as indica able microstructures. 15. A dispersion according to claim 14 wherein the tive of the scope and content of the invention. permeable microstructures comprise a phospholipid. What is claimed is: 1. A dispersion for the pulmonary delivery of a bioactive 16. A dispersion according to claim 15 wherein the agent to a patient, the dispersion comprising: phospholipid is a saturated phospholipid. 17. A dispersion according to claim 14 wherein the (a) a plurality of permeable microstructures, the perme permeable microstructures comprise an inorganic salt. able microstructures comprising at least one bioactive 18. A dispersion according to claim 17 wherein the agent, inorganic salt comprises calcium chloride. (b) a Suspension medium that permeates into the perme 19. A dispersion according to claim 17 wherein the gel to able microstructures. liquid transition temperature of the permeable microstruc 2. A dispersion according to claim 1 wherein the perme tures is greater than 40° C. able microstructures comprise at least one of a phospholipid, 20. A dispersion according to claim 17 wherein the nonionic detergent, nonionic block copolymer, ionic Surfac permeable microstructures and Suspension medium have at tant, biocompatible fluorinated Surfactant or combinations least one of: thereof. 3. A dispersion according to claim 1 wherein the perme (1) a refractive index differential of less than 0.5; or able microstructures comprise a phospholipid. 4. A dispersion according to claim 3 wherein the phos (2) a density differential of less than 0.6 g/cm. pholipid is a Saturated phospholipid. 21. A dispersion according to claim 14 wherein the 5. A dispersion according to claim 3 wherein the perme bioactive agent comprises one or more of antiallergics, able microstructures comprise an inorganic salt. bronchodilators, pulmonary lung Surfactants, analgesics, 6. A dispersion according to claim 5 wherein the inorganic antibiotics, leukotriene inhibitors or antagonists, antihista salt comprises calcium chloride. mines, anti-inflammatories, antineoplastics, anticholin 7. A dispersion according to claim 5 wherein the gel to ergics, anesthetics, anti-tuberculars, imaging agents, cardio liquid transition temperature of the permeable microstruc vascular agents, enzymes, steroids, genetic material, viral tures is greater than 40° C. vectors, antisense agents, proteins, peptides or combinations 8. A dispersion according to claim 1 wherein the perme thereof. able microstructures and Suspension medium have a refrac tive index differential of less than 0.5.