PHARMACOKINETICS OF OSTHOLE IN RAT PLASMA USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A simple high-performance liquid chromatographic method was developed to study the pharmacokinetics of osthole in rat plasma. After addition of an internal standard (paeonol), plasma was deproteinized by aceton itrile for sample clean-up. The drugs were separated on a reversed-pha se column and detected by UV absorption at 323 nm. Acetonitrile-water- diethylamine (50:50:0.1, v/v/v) (pH 3.0, adjusted with orthophosphoric acid) was used as the mobile phase. It was applied to the pharmacokin etic study of osthole in rats after a dose of 10 mg kg(-1) by intraven ous administration. A biphasic phenomenon with a rapid distribution fo llowed by a slower elimination phase was observed from the plasma conc entration-time curve.