OBJECTIVETo develop a HPLC for the determination of plasma concentration of glycyrrhetic acid (GA) and study the pharmacokinetics of GA in rats.

METHODTo sample blood from rat which were injected GA by 1.0 mg x kg(-1) at 0.08, 0.17, 0.25, 0.33, 0.5, 0.75, 1, 2, 3, 4, 6 h and use HPLC to determine the concentration of GA in it, the pharmaeokinetie parameters were accessed by DAS 1.0.

RESULTThe calibration curve was linear (r = 0.999 7) within the range of 50-2 000 ng x mL(-1) for GA in plasma. The average recovery was (105.2 +/- 2.23)%, (102.5 +/- 2.95)%, (98.4 +/- 2.32)%. The within-day and between-day derivation (RSD) were less than 4%. GA was fitted to a two compartment open pharmaeokinetie model in rats. The mainly pharmaeokinetie parameters were: t1/2alpha = (0.153 +/- 0.023) h, t1/2beta = (2.365 +/- 0.866) h, C(max) = (2.074 +/- 0.100) mg x L(-1), CL = (0.715 +/- 0.082) L x h(-1) x kg(-1), V(d) = (2.427 +/- 0.872) L x kg(-1), AUC(0-6 h) = (1.302 +/- 0.151) mg x h(-1) x L(-1).

CONCLUSIONThe method can be used to determine the concentration and to investigate the pharmacokinetics of GA in rat. GA was disposed extensively and rapidly in rats.