LC determination of impurities in azithromycin tablets

A LC method with UV detection for determining azithromycin impurities in tablets as pharmaceutical form has been developed. It is to be employed in routine and stability tests. A linear gradient elution was employed starting with 47% A and 53% B to reach 28% A and 72% B at 48 min. Mobile phase A was KH2PO4 10 mM (H2O) at pH 7.00. B was a mixture methanol: acetonitrile 1:1 (v/v). UV detection was performed at 210 nm. The chromatographic column was Phenomenex Synergi(R) MAX-RP 4 mum 250 x 460 min kept at 50 degreesC. Six impurities were separated and identified and it was possible to quantify five out of the six with reasonable accuracy and precision. (C) 2003 Elsevier B.V. All rights reserved.