Abstract
Amlodipine, a long acting dihydropyridine calcium channel antagonist, is prescribed
worldwide for the treatment of angina and hypertension. The objective of this study
was to compare the pharmacokinetics and to establish bioequivalence of two formulations
of amlodipine. The study was performed at the Clinical Pharmacology Unit, Hospital
de Clínicas, Medical School of Buenos Aires University. This randomized, single blind,
two-period, two-sequence, comparative crossover study was conducted in 24 Caucasian
healthy volunteers. A single oral 10 mg dose of amlodipine besylate (CAS 111470-99-6)
test formulation and reference formulation were administered to the volunteers separated
by a 3-week washout period in a crossover manner. Blood samples for pharmacokinetic
analysis were collected over a period of 144 h after drug administration. Amlodipine
was measured in plasma samples using a validated HPLC method with LC-MS-MS detection.
A non-compartmental method was used for pharmacokinetic analysis. Bioequivalence between
test and reference amlodipine samples were demonstrated as the calculated 90% confidence
interval for the corresponding ratios of log transformed pharmacokinetic parameters
(AUCt, AUC∞ and Cmax) fell within the 80–125% range, the predetermined criterion for pharmacokinetic equivalence.
Key words
Amlodipine besylate, bioequivalence, pharmacokinetics - Calcium channel antagonists,
dihydropyridine - CAS 111470-99-6
