Liquid chromatography method for separation of clindamycin from related substances

A reversed-phase liquid chromatography method has been developed for the se paration of clindamycin from 7-epiclindamycin, clindamycin B, lincomycin, l incomycin B, 7-epilincomycin and other impurities of unknown identity. The method uses a Hypersil ODS, 5 mu m, 250 x 4.6 mm i.d. column maintained at 45 degrees C. The mobile phase comprises acetonitrile-phosphate buffer (1.3 5% v/v phosphoric acid, adjusted to pH 6.0 with ammonium hydroxide)-water ( 35:40:25, v/v) at a flow rate of 1.0 ml/min. UV detection is performed at 2 10 nm. The method was rested on several C-18 columns and showed good robust ness. Robustness was further evaluated by performing a full-fraction factor ial design experiment. The method showed good selectivity, linearity, and r epeatability. It is also suitable for analysis of clindamycin formulations. (C) 1999 Elsevier Science B.V. All rights reserved.