Method of preparing a rapidly dissolving powder of sterile crystalline cefozolin sodium for parenteral administration

Abstract From the Canadian patent

Essentially crystalline cefazolin sodium (7- (1-(1H)-tetrazolylacetamido)-3-2-(5-methyl-1,3,4-thiadiazolyl)thiomethyl-3-cephem-4-carboxylic acid sodium, salt, a standard antibiotic) for parenteral administration is prepared by a freeze-drying process wherein an ethanolwater solution of cefazolin sodium is chilled slowly from room temperature to -10°C. over a 3-12 hour-period and then, rapidly cooled until the mixture is completely solidified before subjecting said frozen solution to a high vacuum and a moderate amount of heat to sublime the frozen solvent therefrom. The resulting powder dissolves rapidly in acceptable pharmaceutical diluents. X-4494