AUTOMATED-DETERMINATION OF CLOMIPRAMINE AND ITS MAJOR METABOLITES IN HUMAN AND RAT SERUM BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ONLINE COLUMN-SWITCHING

A fully automated method including column-switching and isocratic high -performance liquid chromatography (HPLC) was developed for simultaneo us determination of the tricyclic antidepressant clomipramine and its metabolites demethylclomipramine, 2-, 8-, and 10-hydroxyclomipramine, 2-, and 8-hydroxydemethylclomipramine and didemethylclomipramine in se rum. After serum injection into the HPLC system and on-line sample cle an-up on a clean-up column (Hypersil CN; 10X4.6 mm) by an eluent consi sting of 35% acetonitrile and 65% deionized water, the chromatographic separation was performed on an analytical column (LiChrospher CN; 250 x4.6 mm I.D.) by an eluent consisting of 38% acetonitrile and 62% aque ous sodium perchlorate (0.02 M, pH 2.5). The UV detector was set at 26 0 nm. The limit of quantification was about 15 ng/ml for all analytes. The coefficients of variation ranged between 3 and 12% with recovery rates between 64 and 110%. Linear regression analyses revealed coeffic ients of correlation between 0.98 and 0.99. The method could be applie d to therapeutic drug monitoring as well as metabolism studies in man and rat. (C) 1998 Elsevier Science B.V. All rights reserved.