PHARMACOKINETICS OF CRYPTOTANSHINONE AND ITS METABOLITE IN PIGS

AIM: To study the pharmacokinetics and excretion of the antibacterial constituent cryptotanshinone (CT) isolated from the roots of Saliva przewaalskii maxim (Labiatae) and its metabolite tanshinone IIA(TS) in pigs. METHODS: Normal pigs were given CT iv 10 mg.kg^-1. The concentrations of CT and TS in porcine plasma, urine and bile were determined by an HPLC method developed in our laberatory. A waters model 480 instrument was used throughout the experiment. Dibenyl was used as the internal standard at absorption wavelength of 254 nm. A mixture of methanol and water(85∶15) was used as the mobile phase with a flow rate of 1 ml.min^-1, and YWG C18H37 as stationary phase. RESULTS: The method is simple, sensitive and available for pharmacokinetics studies. Plasma drug concentration-time course of CT after iv adminstration of CT was found to be fitted to a two compartment open model and its pharmacokinetic paremeters were as follows: T_1/2α=2.36 min, T_1/2β=64.78 min, AUC=23.83 mg.min.L^-1. TS was detected simultaneously. Peak plasma concentration of TS was reached at about 4.6 minutes after dosing. C_max=0.62　μg.ml^-1, T_1/2β=189.04 min, AUC=22.97 mg.min.L^-1.　The excretion of CT and TS in urine and bile in 24～48 hour was very few after iv and po administration of CT. CONCLUSION: The pharmacokinetics of CT and TS in pigs provided a useful index for clinical trial in animals.