1218-1223 Jing LAJP 3317:Jing

A sensitive and specific HPLC method with internal standard was developed and validated to determine vitexin-2”-O-rhamnoside (VOR) in rat plasma after oral and intravenous administration. VOR presented a very low bioavailability, the P-glycoprotein inhibitors such as verapamil and ketoconazole and absorption promoting agent, i.e. bile salts were therefore respectively applied to investigate the reasons leading to the low oral bioavailability. The results indicated that the oral bioavailability increased about 1.77 and 3.15-fold after co-administration of VOR with verapamil and high concentration of bile salts, respectively, but only a little increased after co-administration with ketoconazole and low concentrations of bile salts.