RETENTION BEHAVIOR OF ANTIEMETIC SEROTONIN ANTAGONISTS IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Granisetron, Ondansetron and Tropisetron, three 5-HT3 antagonists show ing antiemetic activity, were analysed by HPLC on Lipophilic stationar y phases. The addition of an amine or quaternary ammonium salt to the eluents was a powerful tool in the analysis of these basic substances. The influence on chromatographic parameters of pH, ionic strength and various counter-ions in the aqueous phase as well as of different org anic modifiers is discussed. Some of the proposed experimental conditi ons allow a more strictly partition-based separation mechanism and can produce chromatographic parameters suitable for structure-activity st udies. These experimental conditions are also suitable for analysis of the considered compounds in pharmaceutical dosage forms or in biologi cal fluids.