Determination of astragaloside IV in rat plasma after the treatment Buyang Huanwu decoction by RP-HPLC and its pharmacokinetics

OBJECTIVE To develop a HPLC method for the determination of astragaloside Ⅳ in rat plasma. And to investigate astragaloside Ⅳ pharmacokineties in rat. METHODS The separation was performed on a C_(18) column (4.6 mm×250 mm, 5 μm). The detection wavelength was at 203 nm. A solution of acetonitrile-water(35: 65)was used as the mobile phase with the flow rate of 1 mL·min~(-1). The temperature was 45℃. The pharmacokinetic parameters were evaluated with 3P87. RESULTS The calibration curve was linear in the range from 2.4 to 12 μg (r=0.9996). The average recovery was (100.2±1.103)% and RSD was 1.100%. The pharmacokinetic parameters of astragaloside Ⅳ was as following: t_(1/2α) was 1.392 h; t_(1/2β) was 14.24 h; K_1 was 0.1624 h~(-1); K_(21) was 0.3045 h~(-1); K_(10) was 0.07958 h~(-1). The pharmacokinetic parameters of total glycoside were as following: t_(1/2α) was 2.641 h; t_(1/2β) was 37.12 h; K_(12) was 0.1283 h~(-1); K_(21) was 0.1071 h~(-1); K_(10) was 0.04574 h~(-1). CONCLUSION The method is rapid, simple anti easy to use for the determination of astragaloside Ⅳ in rat plasma after the treatment of Buyang Huanwu decoction. The pharmacokinetics of astragaloside Ⅳ in rat can be discribed by two compartmental model.