PROCESS FOR PREPARING CEPHALOSPORIN SALTS

CRYSTALLINE SULFURIC, DI-NITRIC, MONO-HYDROCHLORIC DI-HYDROCLORIC, AND DI AND SESQUIORTHOSPHOSPHORIC ADDITION SALTS OF 7--3--3-CEPHEM-4-CARBOXYLATE ARE STABLE EVEN AT ELEVATED TEMPERATURES. THE CRYSTALLINE SURFURIC ACID ADDITION SALT IS MADE BY FORMING AN ADMIXTURE OF (A) AT LEAST ONE MOLAR EQUIVQLENT OF SULFURICACID 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, WASHINGAND DRYING. THE CRYSTALLINE MONOHYDROCHLORIDE, 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.