Pharmacokinetic and oral bioavailability study of schaftoside in rats

A simple and sensitive LC-tandem mass spectrometry method was established and validated for the determination of schaftoside in rat plasma. After prepared by protein precipitation with acetonitrile, schaftoside and internal standard were separated on a Waters HSS T3 column using acetonitrile containing 0.1% formic acid and 0.1% formic acid in water as the mobile phase by gradient elution. The method showed excellent linearity over the range of 0.5-500 ng/mL with acceptable intra- and inter-day precision, accuracy, matrix effect, and recovery. The stability assay indicated that schaftoside was stable during the sample acquisition, preparation, and storage. The method was applied to a pharmacokinetic study of schaftoside in rats. The result suggested that after intravenous administration at a dose of 1 mg/kg, schaftoside was quickly eliminated from the plasma with an elimination half-life of 0.58 h. After oral administration at doses of 5, 10, and 20 mg/kg, schaftoside was quickly absorbed into the plasma and reached the peak concentration (C_max) of 45.1-104.99 ng/mL at 0.67-1.17 h. The increase of exposure (area under the curve) was linear with the increase of dose. The oral bioavailability was 0.42%-0.71% in the range of 5-20 mg/kg.