United States Patent (19) 11 4,111,203 Theeuwes (45) "Sep
Total Page:16
File Type:pdf, Size:1020Kb
United States Patent (19) 11 4,111,203 Theeuwes (45) "Sep. 5, 1978 54) OSMOTIC SYSTEM WITH MEANS FOR Primary Examiner-Benjamin R. Padgett MPROVING DELVERY KNETCS OF Assistant Examiner-T. S. Gron SYSTEM Attorney, Agent, or Firm-Paul L. Sabatine; Thomas E. 75 Inventor: Felix Theeuwes, Los Altos, Calif. Ciotti; Edward L. Mandell 73) Assignee: Alza Corporation, Palo Alto, Calif. 57 ABSTRACT * Notice: The portion of the term of this patent An osmotic system for delivering a beneficial agent is subsequent to Sep. 5, 1995, has been disclosed. The system comprises a wall surrounding a disclaimed. compartment and has a passageway through the wall for delivering agent from the compartment. The wall is (21) Appl. No.: 744,089 formed of a material permeable to the passage of an (22 Filed: Nov. 22, 1976 external fluid and impermeable to the passage of agent. 51) Int. Cl’............................................. A61M31/00 The compartment contains an agent that is soluble in 52 U.S. C. ..................................... 128/260; 206/0.5; the fluid and exhibits an osmotic pressure gradient 222/130; 222/193; 222/389; 222/395; 222/491; across the wall against the fluid, or the compartment 424/19 contains an agent that has limited solubility in the fluid 58) Field of Search ............... 128/260, 261,268, 272; and exhibits a limited osmotic pressure gradient across 424/15, 19-22, 33, 37; 222/491,395, 193,389, the wall against the fluid. The compartment also con 130; 206/0.5 tains means for increasing the amount of agent deliv ered from the system. The means comprises a film sur (56) References Cited rounding an osmagent with the film formed of a mate U.S. PATENT DOCUMENTS rial permeable to fluid, impermeable to osmagent and 3,247,066 4/1966 Milosovich, Jr. .................... 128/260 movable from an initial to an expanded state. In opera 3,732,865 5/1973 Higuchi et al. ...................... 128/260 tion, agent is delivered from the system through the 3,760,805 9/1973 Higuchi................................ 128/260 passageway at a controlled rate by fluid being imbibed 3,760,984 9/1973 Theeuwes ............................ 128/260 through the wall into the compartment to produce a 3,828,777 8/1974 Ness ..................................... 128/260 solution or suspension containing agent, and for imbibi 3,916,899 11/1975 Theeuwes et al. ................... 128/260 3,948,254 4/1976 Zaffaroni............................. 128/260 tion by the means causing it to concentrate the solution 3,952,741 4/1976 Baker .......... 128/260 or suspension, expand and fill the compartment, 3,977,404 8/1976 Theeuwes ... 128/260 whereby agent is released at a rate controlled by the 3,993,073 11/1976 Zaffaroni ........ 128/260 permeability of the wall, the oosmotic pressure gradient 4,008,719 2/1977 Theeuwes et al. ... 128/260 across the wall, and the rate of imbibition and expansion 4,014,334 3/1977 Theeuwes et al. ... 128/260 of the means over a prolonged period of time. 4,016,880 4/1977 Theeuwes et al. ... 128/260 4,036,227 7/1977 Zaffaroni et al. .................... 128/260 4,036,228 7/1977 Theeuwes ............................ 128/260 13 Claims, 11 Drawing Figures U.S. Patent Sept. 5, 1978 sheet 1 of 2 4,111,203 U.S. Patent Sept. 5, 1978 Sheet 2 of 2 4,111,203 Lif m al O2 - Lut 2 C. CH - - C o SS ed C Co i Fl G. s TIME, HOURS ; 2 3 4 5 6 7 8 9 TO 2 3 4 5 TIME, HOURS -H 4,111,203 1. 2 hances the amount of these latter agents delivered at a OSMOTC SYSTEM WITH MEANS FOR controlled rate and continuously over a prolonged per IMPROVING DELVERY KINETCS OF SYSTEM iod of time by using means to improve the delivery kinetics and the amount of agent delivered from the CROSS-REFERENCE TO RELATED osmotic system. The osmotic system with the means APPLICATION also can optionally deliver increased amounts of very This application is copending with my application soluble or practically insoluble agents as pure agents U.S. Ser. No. 743,760 filed on Nov. 22, 1976. This appli substantially free of any osmotically effective com cation and application Ser. No. 743,760 are both as pounds being mixed therewith. A mathematical presen signed to the ALZA Corporation of Palo Alto, Calif. 10 tation pertaining to the instant subject matter is known in J. Pharm. Sci, Vol. 64, No. 12, pages 1987 to 1991, FIELD OF THE INVENTION 1975. This invention pertains to an osmotic delivery sys tem. More particularly, the invention relates to an os OBJECTS OF THE INVENTION motic system manufactured in the form of an osmotic 15 Accordingly, it is an immediate object of this inven device comprising a semipermeable wall surrounding a tion to provide an improved osmotic system for the compartment containing an agent and a means for im controlled and continuous delivery of an active agent proving the delivery kinetics of the system over a pro over a prolonged period of time which system over longed period of time. comes the problems known to the prior art. 20 Another object of the invention is to provide an os BACKGROUND OF THE INVENTION motic system that can deliver essentially all of its agent Osmotic delivery systems manufactured in the form at a controlled and constant rate continuously over a of osmotic devices for delivering a beneficial agent to prolonged period of time. an environment of use are known to the art in U.S. Pat. Another object of the invention is to provide an os Nos. 3,845,770 and 3,916,899. The systems disclosed in 25 motic system for the delivery of a beneficial agent com these patents comprise a semipermeable wall that sur prising means that improves the delivery kinetics of the rounds a compartment containing an agent. The wall is system. permeable to an external fluid, substantially imperme Still another object of the invention is to provide an able to agent, and there is a passageway through the osmotic system housing a delivery means useful for wall for delivering the agent from the system. These 30 increasing the amount of all kinds of agents delivered systems release agent by fluid being continuously in from the system. bibed through the wall into the compartment at a rate Still yet another object of the invention is to provide determined by the permeability of the wall and the an osmotic system comprising a delivery means for osmotic pressure gradient across the wall to produce a increasing the amount of both very soluble or practi solution of soluble agent, or a solution of an osmotic 35 cally insoluble agents delivered from the system. attractant containing an agent that has limited solubility Yet another object of the invention is to provide an in the fluid, which solution in either operation is dis osmotic system having means for continuously chang pensed from the system. These systems are extraordi ing the internal volume of the system thereby maintain narily effective for delivering both an agent that is solu ing the solution or suspension in the system saturated ble in the fluid and exhibits an osmotic pressure gradient with agent for constant release over time. across the wall against the fluid, and for delivering an Still another object of the invention is to provide an agent that has limited solubility in the fluid and is ad osmotic system having means for uptaking fluid for mixed with an osmotically effective compound that is maintaining excess solid agent in the solution or suspen soluble in the fluid and exhibits an osmotic pressure sion for the controlled release of the agent over time. gradient across the wall against the fluid. While the 45 Still a further object of the invention is to provide an above systems are outstanding and represent a pioneer osmotic system that can maintain the major amount of advancement in the delivery art, and while they are agent inside the system present as a saturated solution or endowed with ideal delivery kinetics useful for deliver saturated suspension with excess solid dispersed therein ing numerous beneficial agents at a controlled rate and throughout the time agent is released from the system. continuously to environments of use, there is an occa 50 Yet still a further object of the invention is to provide sional instance where the delivery kinetics of the system an osmotic therapeutic system that can administer a can be unexpectedly improved to lead to more desirable complete pharmaceutical regimen comprising soluble to results. For example, the rate of agent delivered by the very soluble or limited soluble to practically insoluble system is constant for most agents as long as excess solid agents at a constant rate to animals including warm agent is present in the system with its rate declining 55 blooded animals and humans for a particular time per parabolically towards zero as the agent's concentration iod, the use of which requires intervention only for decreases below saturation. That is, both the solubility initiation and possibly termination of the regimen. and the density of the agent influence the amount of Other objects, features and advantages of the inven agent delivered at a constant rate, and that amount tion will be more apparent to those skilled in the art delivered at a declining rate is proportional to the solu 60 from the following detailed specification, take in con bility of the agent and inversely proportional to its den junction with the drawings and the accompanying sity. These actions often make it difficult to deliver claims. substantially all of the agent and thereby obtain the full benefit of the agent's specific therapeutic effect, particu SUMMARY OF THE INVENTION larly when the agent is very soluble or practically insol 65 This invention concerns an osmotic system for dis uble in the fluid and concomitantly a portion of the pensing a beneficial agent to an environment of use.