Pharmacokinetics and Bioequivalence Study of a Generic Amlodipine Tablet Formulation in Healthy Male Volunteers

Abstract

Two different tablets containing amlodipine besylate (CAS 111470-99-6) (Vazkor^© 10 mg tablet as test preparation and 10 mg tablet of the originator product as reference preparation) were investigated in 18 healthy male volunteers in order to compare the bioavailability and prove the bioequivalence between both treatments after oral single dose administration. The study was performed according to an open-label, randomized, two-period cross-over design with a wash-out phase of 21 days.

Blood samples for pharmacokinetic profiling were taken up to 144 h post-dose, and amlodipine plasma concentrations were determined with a validated LC-MS/MS method.

Maximum plasma concentrations (C_max) of 6,183.7 pg/ml (test) and 5,366.7 pg/ml (reference) were achieved. Areas under the plasma concentration-time curve (AUC_0-∞)of 267,231.0 pg · h/ml (test) and 266,061.7 ng · h/ml (reference) were calculated. The median t_max was 5.6 h (test) and 6.1 h (reference). Plasma elimination half-lives (t_1/2) were 46.46 h (test) and 45.34 h (reference).

Both primary target parameters AUC_0→∞ and C_max were tested parametrically by analysis of variance (ANOVA); 90% confidence intervals were between 93.20%-107.16% (AUC_0→∞ and 103.36%-123.13% (C_max)- Bioequivalence between test and reference preparation was demonstrated since for both parameters AUC and C_max the 90% confidence intervals of the T/R-ratios of logarithmically transformed data were in the generally accepted range of 80%–125%.

Key words

Amlodipine, besylate salt, bioequivalence, pharmacokinetics - Calcium antagonists, dihydropyridine - CAS 88150-42-9 - CAS 111470-99-6 - Vazkor©