摘要:
The crystalline dihydrochloride of a specific cephalosporin derivative is stable to heat and retains its antibacterial activity even after storage over long periods at high temperature. The crystalline dihydrochloride can be obtained by removing protective groups from the cephalosporin derivative wherein the amino group and carboxy groups are protected and then crystallizing the cephalosporin derivative from a hydrochloric acid aqueous solution. The crystalline dihydrochloride is useful for pharmaceutical preparations.