METHOD FOR PREPARING AZITHROMYCIN IN FORM OF NONCRYSTALLINE AND CRYSTALLINE DIHYDRATE

摘要

PROBLEM TO BE SOLVED: To provide a method for preparing Azithromycin being a semi- synthetic macrolide having an excellent antibacterial activity against a gram-positive bacteria or a gram-negative bacteria in the form of non-crystalline and crystalline dihydrate. SOLUTION: This invention relates to the method for preparing non- crystalline 9-deoxo-9a-aza-9a-methyl-9a-homoerythromycin A (Azithromycin) by lyophilizing an aliphatic alcohol solution or a cyclic ether solution of crystalline Azithromycin.