Pharmacokinetics of Tetrandrine Alginate Calcium Sustained Release Gel Pellets in Dogs

OBJECTIVE: To study the pharmacokinetics of tetrandrine(TET)sustained release gel pellets in dogs.METHODS: The dogs were assigned to receive single oral dose of sustained release gel pellets or common tetrandrine alginate calcium tablets by crossover self-control design.Plasma concentrations of tetrandrine alginate calcium were determined by RP-HPLC and the pharmacokinetic parameters were computed with 3P97 pharmacokinetic software.RESULTS: The tmax,Cmax,AUC0→∞ of TET sustained-release gel pellets were 5.67 and 2.5 h,2.67 and 3.53 mg·L-1,29.75 and 19.03 mg·h·L-1 respectively.the relative bioavailability is(106.13±14.41)%.The pharmacokinetics in vivo was in line with one-compartment first order absorption process.There existed a good correlation between release in vitro and absorption in vivo(r=0.979 8).CONCLUSION: Compared with the common TET tablets,TET sustained release gel pellets had smooth concentration and significantly prolonged release,meeting the expected delayed release efficacy.