Bioequivalence study of entecavir tablets in healthy Chinese subjects under fasting condition
Objective To evaluate the pharmacokinetics and bioequivalence of two entecavir tablets under fasting condition in Chinese healthy volunteers.Methods A single oral dose of 0.50 mg entecavir test and reference formulations was given to 30 healthy volunteers in the fasting state according to two randomized open-label crossover clinical studies.Plasma concentrations were determined by HPLC-MS/MS after deproteinized with acetonitrile.The pharmacokinetic parameters were calculated by WinNonlin 6.4.The bioequivalence of entecavir tablets test and its reference in the fasting state were evaluated respectively.Results In the fasting state,the main pharmacokinetic parameters of entecavir were as follows:Cmax were(4 390.00±1 257.56)and(4 421.00±1 239.55)pg·mL-1;tmax were 0.67(0.33,2.00)and 0.75(0.50,2.00)h;t1/2were(29.71±14.50)and(35.43±16.58)h,AUC0_72h were(12 252.43±2 671.28)and(12 063.43±2 151.50)pg·mL-1·h.The 90%confidence intervals of the mean ratio of Cmax,AUC0-72h and AUC0-∞ of the text and reference formulations were all within the equivalent interval of 80.00%-125.00%.Conclusion The entecavir tablets test and its reference were bioequivalent in the fasting state.
entecavirfastingbioequivalencepharmacokineticshigh-performance liquid chromatography-tandem mass spectrometry