Determination and pharmacokinetic study of tussilagone in rat plasma by RP-HPLC method.

A simple and rapid high-performance liquid chromatographic method was used to study the pharmacokinetics of tussilagone, one of the main bioactive constituents in the flower buds of Tussilago farfara L. of traditional Chinese medicines, in rat plasma. Plasma was deproteinized by ethyl acetate for sample clean-up. The drugs were separated on a Dikma Diamonsil C18 column (4.6 x 250 mm, 5.0 microm), and detected by UV absorption at 220 nm. Methanol-water (75:25, v/v) was used as the mobile phase. It was applied to the pharmacokinetic study of tussilagone in rats after a dose of 5 mg/kg by intravenous administration and a dose of 200 mg/kg by intragastrical administration. A biphasic phenomenon with a rapid distribution followed by a slower elimination phase was observed from the plasma concentration-time curve by intravenous administration, while the plasma concentration-time curve of tussilagone conformed to a one-compartment model by intragastrical administration. The absolute bioavailability of tussilagone is about 1.31%.