Simultaneous Determination of Antihypertensive Agent Cromakalim and Its Major Metabolites in Human Urine by High Performance Liquid Chromatography

Abstract

A high performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of Cromakalim, a novel antihypertensive agent, and its major metabolites in human urine. The urine sample was first applied onto a disposable cartridge column of octadecyl silica gel (ODS) for solid phase extraction. The charged sample was then washed with an alkaline solution prior to its elution with aqueous methanol. The eluate was introduced into an HPLC system equipped with an ODS column and was analyzed by a gradient elution technique. In combination with fluorescence detection, this analytical method realized a sensitive determination of Cromakalim and its three major metabolites, simultaneously, in human urine. Urine samples from preclinical trials (Phase I study) conducted on healthy Japanese volunteers were successfully assayed using this new method.