Bioequivalence of Solifenacin Succinate Tablets in Healthy Subjects
Objective To assess the bioequivalence between the test and reference formulations of solifenacin succinate tablets following a single oral dose under fasting conditions in healthy Chinese volunteers.Methods The study was designed as single-center,randomized,open,self-crossover.Thirty healthy volunteers were recruited in fasting conditions.Subjects were assigned to receive a single oral dose of the test or reference formulation per period at a dose of 5 mg.The plasma concentration of solifenacin was analyzed by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The major pharmacokinetic parameters were calculated by WinNonlin 8.4,and the bioequivalence was evaluated.Results The main pharmacokinetic parameters of single oral solifenacin succinate under fasting conditions for the test and reference preparations were as follows:Cmax(7.31±2.27)µg·L-1 and(7.40±2.35)μg·L-1,AUC0-,(417.00±142.00)h·μg·L-1 and(429.00±156.00)h·μg·L-1,AUC0-∞(502.00±201.00)h·μg·L-1 and(511.00±214.00)h·μg·L-1,Tmax 5.00 hours and 5.00 hours,t1/2(62.70±16.30)hours and(60.70±16.60)hours.The relative bioavailability was 97.85%for AUC0_t,97.01%for AUC0-∞.The 90%confidence intervals of the geometric mean ratios of the main pharmacokinetic parameters(Cmax,AUC0-t,AUC0-∞)of the two preparations under fasting conditions were all 80.00%-125.00%.Conclusion The test and reference preparations of solifenacin succinate tablets are bioequivalent under fasting conditions.