ABSTRACT
A quantitative method for epimedin A, B, C and icariin in rat plasma was established using LC-MS/MS after intermuscular administration of Chuankezhi injection to rat. Chromatographic separation was performed on an Agilent Eclipse XDB-C18 column (150 mm×2.1 mm, 5.0 μm) at 40℃. Mobile phase consisted of acetonitrile -0.1% formic acid in water (35:65), and the flow rate was 0.22 mL·min-1. The LC effluent was detected and analyzed using an ESI-triple quadrupole tandem mass spectrometer under the multiple reaction monitoring (MRM) in the negative ion mode. The plasma samples were treated with solid phase extraction prior to LC-MS/MS analysis. As a result, all of the four analytes displayed a good linearity over the concentration of 1-1000 ng·mL-1. The RSDs of intra-day and inter-day assays were less than 5.99% and 10.16%, respectively. The relative recovery of each analyte was between 88.1%-101.1% with RSD<7.9% and the absolute recovery was between 72.0%-86.6% (RSD<6.3%). In conclusion, the established method shows good specificity, sensitivity and efficiency for quantifying the four flavonoid glycosides contained in rat plasma.
ABSTRACT
To study pharmacokinetic characteristics of epimedin A, B, C and icariin after intermuscular administration of Chuankezhi injection to rat. The established RRLC-MS/MS method was applied for simultaneous determination of four analytes in rat plasma and calculating their pharmacokinetic parameters. As a result, each analyte showed a good linear relationship in the concentration range of 1-1 000 μg•L⁻¹.The intra-day precise was 96.9%-107.5% with RSD<5.99%, inter-day precise was 92.3%-105.0% with RSD<10.16%. The relative recovery of four analytes was 88.1%-101.1% with RSD<7.9% and their absolute recovery was 72.0%-86.6% with RSD<6.3%. After intermuscular administration of Chuankezhi injection, the plasma concentration of four flavonoid glycosides rapidly arose to peaks at about 10 min, and then quickly declined in rat. Tmax of epimedin A, B, C and icariin was 0.21, 0.19, 0.16 and 0.49 h, respectively, and their mean elimination half-life(t1/2z) was 0.60, 0.62, 0.47 and 0.49 h. The established method was validated to be sensitive, rapid and specific for determination of the four analytes. Serum concentration of 4 species of epimedium flavonoids in Chuankezhi injection was low, and their absorption and elimination seem quickly, displaying similar pharmacokinetic characteristics in this study.