Hanmi Pharm. Co., Ltd.

Hanmi Pahrm. Co., Ltd.

Mi-Ra Seong

Gwan-Sun Lee

Kwee-Hyun Suh

Nam-Du Kim

Gi-Jeong Kim

Sang-Min Yoon

Sang-Min Yun

A clathrate of azithromycin hydrate with 1,2-propyleneglycol is much less hygroscopic than azithromycin hydrate or crystals known in the art, therefore, it can be useful for the preparation of a medicine for treating various microbial infections.

Clathrate of azithromycin hydrate with 1,2-propyleneglycol, method for the manufacture thereof and pharmaceutical composition comprising same

Clarithromycin can be easily prepared by reacting erythromycin A N-oxide with a methylating agent to obtain 6-O-methylerythromycin A N-oxide; and treating 6-O-methylerythromycin A N-oxide obtained above with a reducing agent in a high yield.

Method of preparing clarithromycin

High purity Form II crystals of clarithromycin can be easily prepared in a high yield by a process comprising the steps of: protecting the 9-oxime hydroxy group of erythromycin A 9-oxime or a salt thereof with a tropyl group and the 2&prime;- and 4&Prime;-hydroxy groups with trimethylsilyl groups; reacting 2&prime;,4&Prime;-O-bis(trimethylsilyl)erythromycin A 9-O-tropyloxime with a methylating agent; removing the protecting groups and the oxime group of 2&prime;,4&Prime;-O-bis(trimethylsilyl)-6-O-methylerythromycin A 9-O-tropyloxime to obtain crude clarithromycin; treating the crude clarithromycin with methanesulfonic acid in a mixture of a water-miscible organic solvent and water to obtain crystalline clarithromycin mesylate trihydrate; and neutralizing the crystalline clarithromycin mesylate trihydrate with aqueous ammonia in a mixture of a water-miscible organic solvent and water.

Method of preparing form II crystals of clarithromycin

Pure Form II crystals of clarithromycin can be prepared by a simple, high-yield process comprising the steps of treating crude clarithromycin or different crystal forms of clarithromycin with formic acid in an organic solvent to obtain crystalline clarithromycin formate and neutralizing the clarithromycin formate with a base in a mixture of water and a water-miscible organic solvent.

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Yongin-si, South Korea

Mi-Ra Seong