High-performance liquid chromatography of clomipramine and metabolites in human plasma and urine

An isocratic, high-performance liquid chromatography method has been developed for simultaneous determination of the tricyclic antidepressant clomipramine and six metabolites: desmethylclomipramine, 2- and 8-hydroxy-clomipramine, 2- and 8-hydroxydesmethylclomipramine and didesmethyl-clomipramine in plasma and urine. In addition, clomipramine N-oxide was determined in the unconjugated fraction of urine. The method is based on a three-step liquid-liquid extraction, the chromatographic eluent was 30% acetonitrile and 70% aqueous sodium perchlorate solution, pH 2.5, and the UV detection was performed at 220 nm. The method was applied to the analysis of samples followed by oral doses of clomipramine to patients and healthy volunteers.