Determination of imperatorin in rat plasma by reversed-phase high-performance liquid chromatography after oral administration of Radix Angelicae dahuricae extract.

A simple high-performance liquid chromatographic (HPLC) method has been developed for the determination of imperatorin in rat plasma and applied to a pharmacokinetic study in rats after administration of Radix Angelicae dahuricae extract. After addition of fluocinonide as an internal standard (IS), plasma samples were extracted with diethyl ether. HPLC analysis of the extracts was performed on a Diamonsil C18 analytical column using methanol-water (70:30, v/v) as the mobile phase. The UV detector was set at 254 nm. The standard curve was linear over the range 0.04-4.0 microg/mL. The lower limit of quantification was 0.04 microg/mL. The HPLC method developed could be easily applied to the determination and pharmacokinetic study of imperatorin in rat plasma after giving the animals Radix Angelicae dahuricae extract.