SIMULTANEOUS MEASUREMENT OF THE MAJOR METABOLITES OF DOLASETRON MESILATE IN HUMAN URINE USING SOLID-PHASE EXTRACTION AND HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A method based on solid-phase extraction and high-performance liquid c hromatography (HPLC) has been developed for the simultaneous quantitat ion of the principal active metabolites of dolasetron mesilate [i.e. M DL 74,156 (II), MDL 102,382 (III) and MDL 73,492 (IV)] in human urine. The method has been validated over the concentration range of 200-500 0 pmol/ml for all three metabolites. Within-day and day-to-day coeffic ients of variation were less than 9 and 14%, respectively, for the thr ee metabolites. The method allowed the simultaneous quantitation of II I, IV and II and the evaluation of the urinary excretion of these meta bolites in human urine following the administration of dolasetron mesi late.