determination of captopril by hplctandem mass spectrometry: application in a bioequivalence study

Objective: To assess three different captopril tablet formulations of 25mg for their bioavailability (Capoten® as the reference formulation and Captopril from FURP and Farmanguinhos as the test formulations) in 24 healthy volunteers of both sexes. Methods: The volunteers were free from serious disease, as assessed by physical and psychiatricexamination, EKG, and laboratory tests. The study was open, with a three-period crossover design and a five-day washout period. Plasma samples were obtained over a 24-hour interval.Captopril concentrations were determined by reversed phase liquid chromatography tandem mass spectrometry (LC-MS-MS). Results: The geometric mean for Capoten® /Captopril- FURP 25 mg was 96.9 % for AUC0-24, 95.58 % for AUC0-∞, and 98.17% for Cmax. The 90% confidence intervals (CI) were 84.8-100.65%, 88.5-109.42% and 82.52-116.8%, respectively. The geometric mean for Capoten®/Captopril-Farmanguinhos 25 mg was 99.63 % for AUClast, 98.52% for AUC0-∞, and 95.52 for Cmax. The 90% CI were 87.23-113.8%, 86.06-112.79% and 80.29-113.64%, respectively. Therefore, the 90% CI for Cmax, AUClast, AUC0-∞ were within the 80-125% interval proposed by the Food and Drug Administration. Conclusion: Captopril- FURP and Captopril-Farmanguinhos 25 mg tablets were bioequivalent to Capoten® 25 mg,according to both the rate and extent of absorption.