AN IMPROVED HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF CHLORPROPAMIDE IN HUMAN PLASMA

Samples were extracted with dichloromethane and the organic layer evap orated to dryness. The residue was dissolved in methanol, and 10 mul a liquot injected onto the column. Tolbutamide was used as the internal standard for chlorpropamide. The UV detector response was linear over the range 0-200 mug ml-1 with a correlation coefficient of 0.999; dete ction limit: 0.002 mug ml-1. Within-day and between-day assay variatio n was generally less-than-or-equal-to 7 %. No interference from endoge nous constituents was observed. The utility of the method was demonstr ated by determining chlorpropamide in samples from six healthy volunte ers following a single oral dose of 250 mg. The procedure is simple an d requires small volumes of plasma.