DETERMINATION OF A NEW ANTIULCER AGENT, YJA-20379-1 IN PLASMA, URINE,BLOOD, AND TISSUE-HOMOGENATES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A high-performance liquid chromatographic method was developed for the determination of a new antiulcer agent, XJA-20379-1, in human plasma and urine, and rat blood and tissue homogenates. The sample preparatio n was simple: a 2.5-volume of acetonitrile was added to the biological sample to deproteinize it. A 50-mu l aliquot of the supernatant was i njected onto a C-18 reversed-phase column. The mobile phase employed w as methanol -0.1 M Sorensen phosphate buffer of pH 7.0 - H2O (80:2:15, v/v/v), and was run at a flow-rate of 0.7 ml/min. The column effluent was monitored by ultraviolet detector at 254 nm. The retention time f or YJA-20379-1 was approximately 6.3 min. The detection limits for YJA -20379-1 in human plasma and urine, and rat tissue homogenate (includi ng blood) were 50, 100, and 100 ng/ml, respectively. The coefficients of variation of the assay (within-day and between-day) were generally low (below 9.44%) for the human plasma and urine, and rat blood and ti ssue homogenate. No interference from endogenous substances were found .