AIMTo establish a solid phase extraction-high performance liquid chromatographic (SPE-HPLC) method for determining plasma scutellarin concentration, and study its pharmacokinetics after i.v. breviscapine in rabbits.

METHODSMethanol-water-phosphoric acid (50:50:0.5) mixture was used as mobile phase, Nucleosil C18 column (250 mm x 4.6 mm ID) was selected. The wavelength of UV detection was 335 nm. Fifteen rabbits, randomized into 3 groups, were given breviscapine i.v. at the dose of 10, 20 and 40 mg.kg-1. Scutellarin in plasma was determined by SPE-HPLC method.

RESULTSLinearity was obtained over the range of 0.02-10.0 mg.L-1 of scutellarin. The method recovery was 96.15%-99.31%; the within-day and between-day RSDs were all below 10%. After i.v. 10, 20 and 40 mg.kg-1 of breviscapine to rabbits, the concentration-time curve of scutellarin fitted to a three compartment model. The main pharmacokinetic parameters showed no significant difference between low and medium doses, but the difference was significant between high dose and other doses.

CONCLUSIONThis assay method was accurate, sensitive, simple and suitable for the measurement of plasma scutellarin concentration. The pharmacokinetic characteristics were found to fit a three-compartment model following i.v. injection of breviscapine to rabbits. The changes of drug concentration in vivo exhibited linear kinetics ove the dosage range of 10-20 mg.kg-1, but when the dosage was 40 mg.kg-1, the linear kinetic properties disappeared.