Simultaneous determination of baicalin, baicalein, wogonoside, wogonin, scutellarin, berberine, coptisine, ginsenoside Rb1 and ginsenoside Re of Banxia xiexin decoction in rat plasma by LC-MS/MS and its application to a pharmacokinetic study.

A rapid and high-sensitivity liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for simultaneous determination of nine active constituents (baicalin, baicalein, wogonoside, wogonin, scutellarin, berberine, coptisine, ginsenoside Rb1 and ginsenoside Re) in rat plasma after oral administration of Banxia xiexin decoction (BXD). Biological samples were processed wtih acetone-ethyl acetate (4:1, v/v). The mobile phase consisted of methanol and water (containing 0.1% formic acid) with gradient elution at a flow rate of 0.3 mL/min. Detection was performed on a triple quadrupole mass spectrometer using positive ion and negative ESI in the multiple reaction monitoring mode. The calibration curves for all analytes had good linearity (r > 0.9933). The mean recovery of all the nine active ingredients was >75.2%, and the intra- and inter-day precisions were within 12.0%; the accuracy was between 87.4 and 110.4%. This method was successfully applied to a pharmacokinetic study after administration of BXD. The results of the pharmacokinetic study might be helpful for BXD reasonable clinical application and further studies on mechanism.