Bioequivalence study of enalapril tablets in healthy Thai male volunteers.

Author(s): Lohitnavy O, Lohitnavy M, Taytiwat P, Polnok S

Affiliation(s): Bioequivalence Test Center, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, Thailand.

Publication date & source: 2002-06, J Med Assoc Thai., 85(6):716-21.

Publication type: Clinical Trial; Randomized Controlled Trial

The bioequivalence study of 5-mg enalapril tablets, Enaril (Biolab, Thailand) compared to Renitec (Merck Sharp & Dohme, USA) was conducted in 14 healthy Thai male volunteers following a single dose, two-period, crossover design. Each subject received 4 tablets of 5-mg enalapril tablets of both formulations with a 1-week washout period. Plasma samples collected over a 24-hour period after administration were analyzed by LC/MS/MS. Pharmacokinetic parameters were determined by using non-compartmental analysis. Regarding bioequivalence testing, the 90 per cent confidence intervals of Cmax and AUC(0-infinity) ratios (Enaril/Renitec) of enalapril were 86.3-126.1 per cent and 93.0-118.5 per cent and those of enalaprilat were 86.4-124.1 per cent and 90.3-116.8 per cent. Based on the European bioequivalence guideline, the 90 per cent confidence interval of Cmax and AUC(0-infinity) ratios of both parent and metabolite forms were within acceptable ranges of 70-143 per cent and 80-125 per cent, respectively. It was concluded that Enaril 5 mg tablet was bioequivalent to Renitec 5 mg tablet.