Bioequivalence study of generic amlodipine in healthy Thai male volunteers.
METHODS
To determine the bioequivalence of 10 mg generic amlodipine in healthy male volunteers, the reference and the test formulations were administered as a single oral dose after overnight fasting in a crossover study separated by 2-week washout interval. After dosing, serial blood samples were collected for a period of 144 h. Plasma amlodipine concentrations were determined by LC-MS/MS and the pharmacokinetic parameters were analyzed by non-compartmental analysis.


RESULTS
The mean elimination half-life (t1/2) for the test (40 h) and the reference (44 h) were within the values previously reported. The rate of absorption reflected by tmax had a difference of -0.33 h, with a 90% CI of (-1.52)-0.85 (acceptable range +/- 1.3). Although the tmax of the test (5 h) was faster than the reference (6 h), the mean (90% CI) of the AUC(0-infinity) and Cmax ratios Test/Reference were 0.91 (0.87-0.97) and 1.01 (0.93-1.09), respectively. These values were within the range of 0.80-1.25, thus, the study demonstrated the bioequivalence of the 2 formulations.
Rojanasthien
N
N
Division of Clinical Pharmacology, Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. nrojanas@med.cmu.ac.th
Teekachunhatean
S
S
Jakob
K
K
Gaupp
M
M
Arnold
P
P
Chaichana
N
N
Martin
W
W
D000328:Adult; D017311:Amlodipine / Q000097:blood / Q000493:pharmacokinetics*; D000704:Analysis of Variance; D019540:Area Under Curve; D002121:Calcium Channel Blockers / Q000097:blood / Q000493:pharmacokinetics*; D002626:Chemistry, Pharmaceutical; D016001:Confidence Intervals; D018592:Cross-Over Studies; D006207:Half-Life; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D013785:Thailand; D013810:Therapeutic Equivalency
D002121:Calcium Channel Blockers; D017311:Amlodipine