Simultaneous determination and pharmacokinetics of five bufadienolides in rat plasma after oral administration of Chansu extract by SPE-HPLC method

A sensitive and rapid solid-phase extraction-high performance liquid chromatography (SPE-HPLC) method has been developed for the determination of five bufadienolides, arenobufagin, teliocinobufagin, cinobufotalin, cinobufagin and resibufogenin in rat plasma and applied to a pharmacokinetic study in rats after oral administration of Chansu extract (Venenum Bufonis). Plasma samples were pretreated with solid-phase extraction using Extract-Clean™ cartridges, and the extracts were analyzed by a reversed-phase C18 column on a HPLC system with photodiode array detection (DAD). The calibration curves were linear over the range of 0.10–1.66 μg/ml for arenobufagin, 0.03–1.20 μg/ml for telocinobufagin, 0.01–0.62 μg/ml for cinobufotalin, 0.03–0.70 μg/ml for cinobufagin and 0.02–2.57 μg/ml for resibufogenin, respectively. The limit of quantification was 1.1 ng/ml for arenobufagin, 0.3 ng/ml for telocinobufagin, 9.7 ng/ml for cinobufotalin, 8.8 ng/ml for cinobufagin, 7.7 ng/ml for resibufogenin, respectively. The established method could be easily applied to the determination and pharmacokinetic studies of five bufadienolides in rat plasma after oral administration of Chansu extract.