PROCESS FOR THE PREPARATION OF AZITHROMYCIN DIHYDROCHLORIDE

摘要

The present invention refers to a new process for the preparation of azithromycin dihydrochloride, which is a pharmaceutically acceptable salt of the antibiotic azithromycin useful as an antibacterial agent with a broad-spectrum action, the process compriseing reacting azithromycin dihydrate dissolved in a lower (C1-C4) alcohol or lower (C3-C6) ketone with 1.6 to 2 equivalents of hydrogen chloride gas dissolved in a dry lower (C1-C4) alcohol at a concentration of 12-20% (w/v), at a temperature of from 10.degree.C to 15.degree.C, precipitating the obtained product with a non-solvent at a temperature of from 10.degree.C to 25.degree.C, with the ratio of solvent:non-solvent being from 1:1.8 to 1:8 (v/v), and then isolating the obtained product by filtration.