Process for preparing pure, crystalline penicillin salts

Claim 1

IN A PROCESS FOR PREPARING PURE, CRYSTALLINE SALTS OF PENICILLIN, THE STEPS WHICH COMPRISE ACIDIFYING AN AQUEOUS SOLUTION OF PENICILLIN SALTS CONTAINING AT LEAST ABOUT 15,000 OXFORD UNITS OF PENICILLIN ACTIVITY PER MILLILITER AND ADDING THERETO A SALTING-OUT AGENT SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE ALKALI-METAL, ALKALINEEARTH-METAL, AND AMMONIUM SALTS HAVING INORGANIC ANIONS, EXTRACTING THE ACID FORM OF PENICILLIN THEREFROM WITH A HYDROPHILIC, ORGANIC SOLVENT FOR PENICILLIN AND PENICILLIN SALT, SAID SOLVENT BEING IMMISCIBLE WITH SAID ACIDIFIED AQUEOUS SOLUTION OF PENICILLIN SALTS IN THE PRESENCE OF SAID SALTING-OUT AGENT, ADDING AN ALKALI SELECTED FROM THE GROUP CONSISTING OF THE HYDROXIDE, CARBONATE AND BICARBONATE OF THE DESIRED CATION TO CONVERT THE PENICILLIN IN THE RESULTING ORGANIC-SOLVENT SOLUTION INTO THE DESIRED PENICILLIN SALT, DEHYDRATING AND CONCENTRATING SAID SOLUTION BY DISTILLING UNDER REDUCED PRESSURE AND AT TEMPERATURES BELOW ABOUT 40*C., AND CRYSTALLIZING A PURE PENICILLIN SALT THEREFROM.