Cephalosporin salts and injectable compositions

Abstract

Crystalline sulfuric, di-nitric, mono-hydrochloric, di-hydrochloric, and di- and sesqui-orthosphosphoric acid addition salts of 7-[.alpha.-(2-aminothiazol-4-yl)-.alpha.-(Z)-methoxyiminoacetamido]-3-[(1-methyl-1-pyrrolidinio)methyl]-3-cephem-4-carboxylate are stable even at elevated temperatures. The crystalline sulfuric acid addition salt is made by forming an admixture of (a) at least one molar equivalent of sulfuric acid with (b) zwitterion in an amount so as to be present in the admixture at a concentration of greater than 25 milligrams/ml, causing crystallization, separating the crystals, washing and drying. The crystalline monohydrochloride, dihydrochloride, and orthophosphate salts are prepared by dissolving the zwitterion in the appropriate amount of acid, causing crystallization by adding acetone and isolating the crystals. Physical admixtures of the salts with certain bases in proportions to give a pH ranging from about 3.5 to about 7 on dilution with water provide injectable compositions on dilution.

Description

Claims

1. Temperature stable crystalline salts of 7-[.alpha.-(2-aminothiazol-4-yl)-.alpha.-(Z)-methoxyiminoacetamido]-3-[(1-methyl-1-pyrrolidinio)methyl]-3-cephem-4-carboxylate selected from the group consisting of the sulfuric, di-nitric, mono-hydrochloric, and di-hydrochloric acid addition salts, and orthophosphoric acid addition salts containing 1.5-2 molar equivalents of H.sub.3 PO.sub.4, or solvates thereof in physical admixture with a pharmaceutical acceptable non-toxic organic or inorganic base selected from the group consisting of sodium salts with weak non-toxic anions, N-methylglucamine, lysine and arginine in proportions to provide a pH of about 3.5 to about 7 on dilution of the admixture with water to injectable concentration.

2. A physical admixture as recited in claim 1 wherein the salt and the base are present in proportions to provide a pH of about 4 to about 6 on dilution of the admixture with water to injectable concentration.

3. A physical admixture as recited in claim 2 wherein the base is L(+) lysine.

4. A physical admixture as recited in claim 2 wherein the base is L(+) arginine.