In the present study, we developed a sensitive and efficient high performance liquid chromatography （HPLC） method for the simultaneous determination of three ginsenosides （Rg1, Re, Rb1） in rat plasma. Chromatographic separation was performed on a C18 （150 min×4.6 mm） column utilizing gradient elution profile and a mobile phase consisting of （A） water and （B） acetonitrile. The calibration curve, with a great correlation coefficient greater than 0.998, was linear over the range of 1.0-30.0 μg/mL for ginsenoside Rgl, 0.5-15.0 μg/mL for ginsenoside Re, and 0.5-200.0 μg/mL for ginsenoside Rb1. The intra- and inter-day precisions for three ginsenosides （Rg1, Re, Rb1） were all less than 6.0%, and average recovery, examined at three concentration levels, ranged from 96.1% to 118.6%. The samples was stable within 24 h at 4 ℃ storage, and 30 d at -20 ℃ storage with three freeze-thaw-assay cycles. The low limits of quantification （LOQ） were 1.0, 0.5 and 0.5 μg/mL for Rg1, Re and Rb1, respectively. Taken together, the newly developed method was successfully applied to study the pharmacokinetics of ginsenoside Rg1, Re and Rb1 in rat plasma after intravenous administration of SHENMAI injection （SMI）.
