Pharmacokinetics of gastrodin from Tiangou Jiangya capsule in rats / 中国中药杂志

ABSTRACT

The paper aims to study the pharmacokinetic parameters of gastrodin in rats effected by compound compatibilitiy and different doses of Tiangou Jiangya capsule. The extracts from Gastrodiae Rhizoma( equivalent to gastrodin 16.82 mg x kg(-1) and Tiangou jiangya capsule (equivalent to gastrodin 8.410, 16.82, 33.64 mg x kg(-1)) were oral administrated to rats respectively. The plasma were taken at various time points and treated with acetonitrile to measure the contents of gastrodin by HPLC method. The mean plasma concentration-time data were analyzed by 3P97 pharmacokinetic software and the pharmacokinetic parameters between groups were treated by SPSS 16.0. The results showed that gastrodin in rat was fitted to one-compartment model, Cmax and AUC of Tiangou Jiangya capsule were in direct proportion to oral administration, and t1/2Ka had nothing to do with doses, which indicated that gastrodin was fitted first-order rate transfter process in vivo. Morever, comparison with the Gastrodiae Rhizoma extract, isodose gastrodin in Tiangou Jiangya capsule showed a significant decrease for Cmax, Ke and increase for t1/2Ke, V/Fc, this indicated that compound compatibility can delay the absorbtion of gastrodin, prolong the resident time and promote the distribution in vivo, but its bioavailability is not significantly effected.