Pharmacokinetics and relative bioavailability of compound oleanolic acid soft capsules in rats

Objective To determine the pharmacokinetic parameters of oleanolic acid in compound oleanolic acid soft capsules after intragastric administration in rats, and calculate the relative bioavailability compared to commercial oleanolic acid tablets. Methods The concentration of oleanolic acid in plasma was determined by HPLC-MS method after intragastric administration of oleanolic acid tablets and compound oleanolic acid soft capsules. The relative bioavailability and pharmacokinetic parameters of oleanolic acid were obtained by using the un-compartment dynamics theory. Results The pharmacokinetic parameters of the test and reference preparations after intragastric administration in rats were Tmax1 (0.54±0.25) h and (0.50±0.00) h,Cmax1 (897.28±120.71) ng·mL-1 and (521.92±35.99) ng·mL-1,Tmax2 (3.92±0.20) h and (4.33±0.26) h,Cmax2 (1259.68±77.33) ng·mL-1 and (340.52±31.42) ng·mL-1,AUC0-36 (8106.64±666.55) ng·mL-1·h and (4164.60±559.32) ng·mL-1·h,respectively. The relative bioavailability of the test preparation was 194.66%. Conclusions The pharmacokinetic parameters of the test and reference preparations differed significantly, and the test preparation improved the relative bioavailability of oleanolic acid remarkably.