RESUMO
Objective To study the pharmacokinetic characteristics of clobazam tablet in Chinese healthy subjects and evaluate the bioequivalence of test preparation(T)and reference preparation(R)under fasting or fed conditions.Methods A randomized,open-label,single-dose,two-period,two-way crossover bioequivalence trial was performed.34 healthy subjects were enrolled in fasting study and 30 in fed study.Each subjects received a single dose of T 20 mg or R 20 mg with a washout period of 28 days.Plasma concentrations of clobazam and its active metabolite,N-desmethylclobazam were determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The pharmacokinetic parameters of clobazam and N-desmethylclobazam were calculated by non-compartment model.Geometric mean values for the T/R ratios of clobazam's main pharmacokinetic parameters and their corresponding 90 percent confidence intervals(CI)were evaluated to assess bioequivalence of the two preparations.Results In fasting study,the 90 percent CI of the geometric mean values for the T/R ratios were 94.46 to 103.82 percent for Cmax,99.64 to 103.62 percent for AUC0-tand 99.39 to 103.51 percent for AUC0-∞,respectively.In fed study,the 90 percent CI of the geometric mean values for the T/R ratios of were 93.86 to 106.02 percent for Cmax,100.37 to 104.51 percent for AUC0-tand 100.71 to 104.63 percent for AUC0-∞,respectively.Conclusion In this study,the 90 percent CI of the geometric mean values of Cmax,AUC0-tand AUC0-∞ for T/R ratios were all within the acceptable bioequivalence limits of 80 to 125 percent for clobazam.Therefore two formulations were considered bioequivalent.