RESUMEN
OBJECTIVE To study the effects of disodium cantharidinate on the pharmacokinetic behavior of capecitabine in rats. METHODS Rats were randomly divided into two control groups and two experimental groups with 6 rats in each group. Two control groups were intraperitoneally injected with normal saline， and two experimental groups were intraperitoneally injected with Disodium cantharidinate injection of 0.5 mL/kg， for 7 consecutive days. Eight days after medication， control group 1 and experimental group 1 were given capecitabine 5 mg/kg intragastrically， while control group 2 and experimental group 2 were given capecitabine 5 mg/kg intravenously. Blood samples were collected at different time points after administration. After extraction with ethyl acetate， the concentration of capecitabine in rat plasma was determined by UPLC-MS/MS method using tolbutamide as the internal standard. The pharmacokinetic parameters were calculated by DAS 2.0 software. RESULTS Compared with control group 1， MRT0－∞， cmax， AUC0－30 h， AUC0－∞ and F of experimental group 1 were increased significantly， while CLz/F was decreased significantly （P＜0.01）. Compared with control group 2， t1/2， MRT0－30 h， MRT0-∞， AUC0－30 h and AUC0－∞ of experimental group 2 were increased significantly （P＜0.01）. CONCLUSIONS Disodium cantharidinate can increase the plasma exposure of capecitabine in rats， improve its oral bioavailability， prolong the average residence time， and reduce its clearance rate.