Bioequivalence of losartan capsules in healthy Chinese male volunteers

Objective To evaluate the bioequivalence of losartan potassium capsules and tablets in healthy Chinese male volunteers.Methods A single oral dose of 100 mg of the test or reference preparations was administered to 20 healthy volunteers in a randomized cross-over study.Concentrations of losartan and its active metabolite,E-3174 in the plasma were determined by a newly developed LC-MS/MS method,and the pharmacokinetic parameters were calculated.Results For losartan,the main pharmacokinetic parameters of the test and reference formulations were as follows: Cmax was(846.6±216.7) and(831.2±247.4)μg·L-1,tmax was(0.7±0.3) and(1.0±0.4) h,AUC0→8 was(1 097.4±278.7) and(1 110.2±266.6) μg·h·L-1,t1/2 was(2.3±0.5) and(2.1±0.6) h,respectively.For active metabolite E-3174,the main pharmacokinetic parameters of the test and reference formulations were as follows: Cmax was(1 166.9±324.6) and(1 198.2±301.2)μg·L-1,tmax was(2.0±0.6) and(2.0±0.8) h,AUC0→24 was(6 712.4±2 021.6) and(6 838.6±1 921.2) μg·h·L-1,t1/2 was(8.5±1.5) and(8.5±2.3) h,respectively.Conclusion The two formulations of losartan are bioequivalence.