DETERMINATION OF A NEW ANTIULCER AGENT, YJA-20379-2, IN HUMAN PLASMA AND URINE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A high-performance liquid chromatographic method was developed for the determination of a new antiulcer agent, YJA-20379-2, in human plasma and urine. The sample preparation was simple: 2.5-volume of acetonitri le was added to the biological sample to deproteinize. A 50-mu l aliqu ot of the supernatant was injected onto a C-18 reversed-phase column. The mobile phase employed was methanol - 0.1M Sorensen phosphate buffe r of pH 7.0 - H2O (75:2:25, v/v/v), and was run at a flow-rate of 1.0 ml/min. The column effluent was monitored by ultraviolet detector at 2 95 nm. The retention time for YJA-20379-2 was approximately 7.0 min. T he detection limits for YJA-20379-2 in human plasma and urine were bot h 100 ng/ml. The coefficients of variation of the assay (within-day an d between-day) were generally low (below 9.16%) for both the human pla sma and urine. No interference from endogenous substances was found.