Preparation process of erythromycin thiocyanate
AssigneeHec Pharm Co., Ltd
InventorsHui Xiong, Keyi Zhao, Zhaozheng Deng
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Abstract
Disclosed is a preparation process of erythromycin thiocyanate, which belongs to the pharmaceutical field. The preparation process provided by the invention uses erythromycin or its salt(s) as raw material(s), dissolves it/them in acetone or the mixed solvent containing acetone and obtains erythromycin thiocyanate rich in erythromycin thiocyanate A as the main component and low in the content of impurities. Said erythromycin thiocyanate could be used as the raw material for preparing Azithromycin and Clarithromycin, which meets to the standards made by European Union and US.
Claims21
(canceled)
A method for preparing erythromycin thiocyanate, comprising:
- a) dissolving erythromycin or an erythromycin salt or a mixture thereof in acetone or a mixed solvent comprising acetone under alkaline condition to form a solution of the erythromycin or erythromycin salt;
- b) adding a thiocyanate salt into the solution;
- and
- c) adjusting the pH of the solution to from 6.0 to 8.0;
- and
- forming crystals of erythromycin thiocyanate.
Dependencies are inferred from the claim text.