OBJECTIVETo establish a SPE-HPLC method for analyzing astilbin in rats serum and explore the effects of Yinxieling (YXL) prescription and Smilacis Glabrae Rhizoma on the pharmacokinetic characteristics of effective components.

METHODMale Sprague-dawley rats were administrated YXL and Smilacis Glabrae Rhizoma respectively. At different time points, serum concentration of astilbin was extracted by Solid Phase Extraction (SPE) and determined using HPLC method. Chromatographic separation was achieved on a reversed-phase Phenomenex C18 column with the mobile phase of methanol-acetonitrile-formic acid water solution (0.05% formic acid) and gradient elution, temperature of bar was 24 degrees C, flow rate was 0.8 mL x min(-1).

RESULTThe method showed excellent linearity over the concentration range 0.266-53.1 mg x L(-1) of astilbin (r = 0.996). The extract recoveries were from 79.0% to 89.1%. Significant diffenerce in pharmacokinetic parameter of astilbin including t1/2, Cmax, AUC(0-t), AUC(0-infinity) and MRT were obtained through non-compartment model after oral administration of YXL prescription comparing with Smilacis Glabrae Rhizoma.

CONCLUSIONThe method was applied to a pharmacokinetic study of astilbin. It indicated that the bioavailability of astilbin in YXL enhanced in rats and one of the reasons may be that components of prescription affect the pharmacokinetics of astilbin in vivo.