Stable, crystalline sodium cephalothin prepn. - by freeze-drying aq. alkanol or aq. acetone solns.; used for parenteral injection, after reconstitution

摘要

Prepn. of crystalline sodium cephalothin by a freeze-drying process of 24h comprising (a) dissolving 20-40 wt.% of sodium cephalothin in water contg. 2-10% of a 1-3C alkanol or acetone (b) cooling the soln. to =-20 degrees C (c) heating the soln. to -3 to -10 degrees c, (d) maintaining the soln. at -3 to -10 degrees C for >=3 hr, (e) cooling the soln. to =-20 degrees C, (f) reducing the pressure in the vessel to =1mm Hg, (g) raising the temp. of the vessel to =50 degrees C, without melting the prepn. (h) subliming the solvent to give crystalline sodium cephalothin with a moisture content of =1% and an alkanol or acetone content of =1%. The products are suitable for reconstitution and use as parenteral injections. The rapid cooling to -20 degrees C forms crystals of sodium cephalothin before the solvent is frozen. When the solvent is sublimed the residue remains as crystals. When the initial soln. (a) is sterile, the product is a sterile crystal ready for prepn. of parenteral solns.