US 20020193322A1 (19) United States (12) Patent Application Publication (10) Pub. N0.2 US 2002/0193322 A1 Baiocchi et al. (43) Pub. Date: Dec. 19, 2002 (54) METHOD OF PREPARING Publication Classi?cation PHYSIOLOGICALLY ACCEPTABLE AQUEOUS SOLUTIONS, AND SOLUTIONS (51) Int. C1.7 ..................... .. A61K 31/704; A61K 31/66; THUS OBTAINED A61K 31/60; A61K 31/551; A61K 31/525; A61K 31/522; (76) Inventors: Leandro Baiocchi; Roma (IT); Mauro A61K 31/57 De Gregorio, Roma (IT) (52) us. Cl. ............................ .. 514/33; 514/171; 514/75; 514/263.31; 514/165; 514/217.05; Correspondence Address: 514/220; 514/282; 514/569; OBLON SPIVAK MCCLELLAND MAIER & 514/251 NEUSTADT PC FOURTH FLOOR (57) ABSTRACT 1755 JEFFERSON DAVIS HIGHWAY A physiologically acceptable aqueous solution; and Water ARLINGTON, VA 22202 (US) soluble compositions suitable for obtaining it; comprising a ?rst physiologically acceptable compound of an acidic (21) Appl. No.: 10/058,080 nature and a second physiologically acceptable compound of a basic nature that are able to give rise to a precipitate in (22) Filed: Jan. 29, 2002 Water, characterized in that it also contains a trisubstituted salt of glycyrrhiZic acid in a sufficient quantity to form a (30) Foreign Application Priority Data clear solution in Water. Jan. 30, 2001 (IT) .......................... .. RM2001A 000048 A method for preparing the said solution. US 2002/0193322 A1 Dec. 19, 2002 METHOD OF PREPARING PHYSIOLOGICALLY therapeutically useful concentration, and cases of partial ACCEPTABLE AQUEOUS SOLUTIONS, AND incompatibility in Which it is possible to obtain solutions but SOLUTIONS THUS OBTAINED only in a very restricted range of concentration. [0001] This application is based on application No. [0009] The problem of incompatibility is not solved by RM2001 A 000048 ?led in Italy, the content of Which is separate administration of the solutions of the different incorporated hereinto by reference. pharmacologically active compounds to the patient, unless there is a considerable interval of space and/or time betWeen [0002] The present invention relates to a method of pre the applications. OtherWise, in fact, incompatibility betWeen paring physiologically acceptable aqueous solutions and the tWo pharmacologically active compounds and inactiva Water-soluble compositions suitable for obtaining them, as tion occur at the site of actual application (see, for example, Well as the solutions and the compositions thus obtained. the case of cephalosporins and of aminoglycosides (REFI [0003] More particularly, the present invention relates to page A-249)). In each case separate application, besides physiologically acceptable aqueous solutions and Water being inconvenient, proves completely impossible in some soluble compositions suitable for obtaining them, compris cases, for example When one of the compounds performs the ing a ?rst physiologically acceptable compound of an acidic functions of a preservative. nature, a second physiologically acceptable compound of a basic nature and a trisubstituted salt of glycyrrhiZic acid. STATE OF THE ART [0010] In some cases the problem has been solved by BACKGROUND OF THE INVENTION using speci?c pharmaceutical formulations. Thus, the [0004] In therapeutic and cosmetic practice, both human incompatibility betWeen certain carboxylic acids and certain and veterinary, use is often made of aqueous solutions basic decongestants is eliminated by means of a mixture of containing a carboxylic acid or an organic base, possessing polysorbates and a polyoxamer (US. Pat. No. 5,459,157). loW intrinsic solubility (solubility of the undissociated com Moreover, it should be pointed out that in this case, as in pound). Their sali?cation (generally With alkali metals or other similar cases, the concentration of these additives is hydrophilic amines of loW molecular Weight for the acids, very high (12%) relative to that of the pharmacologically and With hydrogen halides or hydrophilic organic acids of active compounds (0.05-0.1%). loW molecular Weight, for the bases) is employed to provide [0011] GlycyrrhiZic acid, the principal component of the them With adequate solubility. extract of Glycyrrhiza Glabra, Was isolated by Karrer and [0005] Sometimes it is useful to have aqueous solutions Chao and its tricarboxylic acid structure Was established by containing at least one carboxylic acid and at least one RuZicka in 1943 (Merck Index, XII ed., 4515). TWo epimers organic base at the same time. Since solutions With basic pH of glycyrrhiZic acid are knoWn, designated 180. and 186, but are needed for the solubiliZation of Weak organic acids, and the second is the commonest and it is this that is being solutions With acid pH are needed for the solubiliZation of referred to Whenever the nature of the epimer is nots Weak organic bases, such compounds often display a high expressly indicated (Runti, Fondamenti di chimica farma degree of incompatibility in ordinary aqueous solutions ceutica [Fundamentals of pharmaceutical chemistry], Trieste because mutual precipitation occurs on mixing them (see A. 1969, Vol. III, page 265). T. Florence & D. AttWood “Physiochemical Principles of [0012] Various salts of glycyrrhiZic acid, called glycyr Pharmacy”, II edition, Portland Oreg., 1988, p. 154). rhiZinates, have been described in the literature. [0006] Examples of this behaviour that are Well knoWn in [0013] Atypical, commercially available monosubstituted the literature are the solutions of acetylsalicylic acid (lysine salt is the monoammonium salt “GlycamilTM” of the com salt) With chlorpromaZine (hydrochloride) or promethaZine pany Indena of Milan. Typical disubstituted salts are the (hydrochloride) (Repertorio Farmaceutico Italiano 1989 dipotassium salt, “Ritamectant K2TM” of the R.I.T.A. Cor (REFI) page A-578); solutions of furosemide (sodium salt) poration, and the mixed salts of potassium, calcium and With organic bases (REFI, page A-808); solutions of magnesium called “glycyrrhiZines” (US. Pat. No. 4,176, dimemorfan (phosphate) With penicillin (sodium salt) or of 228). A typical trisubstituted salt is the tripotassium salt sodium salicylate (REFI page A-646). (Voss et al., Ber. 70, 122, 1937). [0007] It should be noted, moreover, that the phenomenon [0014] The monosubstituted and disubstituted salts are is rather more complex than might appear at ?rst sight Widely used in the food and pharmaceutical industry, prin because, depending on circumstances, there may be precipi cipally as sWeeteners. tation of the acid compound, or of the basic compound, or [0015] Apart from some mild therapeutic activities that of a mixture of the tWo, or of adducts, knoWn as hydrophobic have been under investigation for several years (antiulcer ion pairs. In this last case, Which is very common, there may be formation of precipitates, even When one of the tWo activity, anti-AIDS activity, treatment of hepatitis B), certain functions of glycyrrhiZic acid and its salts as “adjuvants” in components, for example quaternary ammonium com pounds, has good intrinsic solubility. pharmaceutical formulations have also been described from time to time. [0008] The incompatibility is more or less pronounced [0016] The action of “enhancers” of absorption through depending on the pK, on the nature and on the intrinsic the skin and the mucous membranes is Well documented solubility of the components that determine it. In fact, cases of absolute incompatibility are encountered in practice, in (US. Pat. Nos. 5,183,802; 5,238,917; JP 3099023). Which it is practically impossible to obtain solutions con [0017] Japanese patent JP 10025255 proposes the use of taining the tWo pharmacologically active compounds at any glycyrrhiZic acid, its salts or its esters, for the preparation of US 2002/0193322 A1 Dec. 19, 2002 solid complexes With antiulcer, anti-in?ammatory or anti nature and a second physiologically acceptable compound of histaminic drugs for the purpose of improving their absorp a basic nature that are able to give rise to a precipitate in tion (rate of solution). It is known, hoWever, that the Water, characteriZed in that it also includes a trisubstituted complexes that can be used for increasing the rate of solution salt of glycyrrhiZic acid in suf?cient quantity to form a clear cannot be used for increasing equilibrium solubility (A. J. solution. Repta in “Technique of Solubilation of Drugs” (S. H. [0025] Moreover, in a further aspect, the present invention YalkoWsky ed. Marcel Dekker NY. 1981 page 135 ff.; pages relates to a composition comprising a ?rst physiologically 149 and 151). acceptable compound of an acidic nature and a second [0018] In tWo Japanese patent documents (Jpn Kokai physiologically acceptable compound of a basic nature that 0283,318 and JP 3145432A) reference is made to clear are able to give rise to a precipitate in Water, characterized solutions containing salts of glycyrrhiZic acid, quaternary in that it also includes a trisubstituted salt of glycyrrhiZic ammonium compounds and respectively, sodium condoitr acid in sufficient quantity to form a clear solution When the insulphate, borax and taurine in the ?rst case, and lysoZime said composition is added to Water. (hydrochloride) in the second. In the ?rst case (CA. 113, [0026] For the purposes of the present invention, the 65296x) the salt used is dipotassium glycyrrhiZinate. glycyrrhiZic acid can be either in the form of epimer 180. or [0019] Us. Pat. No. 4,481,187 discloses the use of gly of epimer 186. The latter is preferred, hoWever, because it is