Bioequivalence Study of Donepezil Hydrochloride 10 mg Tablets Under Fasting Conditions

This open label, balanced, randomized, two-treatment, two-period, two-sequence, single dose crossover study was conducted to compare the relative bioavailability of equal doses of the test and reference products under fasted conditions. The study was conducted with 32 (31 completing) healthy adults in accordance with Protocol No. 10940307 (Revision 0). In each study period, a single 10 mg tablet of donepezil hydrochloride was administered to all subjects following an overnight fast of at least 10 hours. The test formulation was donepezil hydrochloride 10 mg tablet (OHM Laboratories, Inc., USA a subsidiary of Ranbaxy Pharmaceuticals, Inc. USA) and the reference formulation was ARICEPT® (donepezil hydrochloride) 10 mg Tablets (Eisai Inc.). The subjects received the test product in one study period and the reference product in the other period; the order of administration was according to the dosing randomization schedule. Subjects were confined at the clinical facility from at least 10 hours prior to dosing until after the 24 hour blood collection. Subjects returned to the clinical facility for the 36, 48, and 72 hour blood sample collection. There was a 28-day interval between treatments. Blood samples were collected pre-dose and at intervals over 72 hours after dosing in each period. The plasma samples from all subjects were shipped to Warnex Bioanalytical Services for determination of donepezil concentrations. Statistical analysis was performed by Ranbaxy Laboratories Limited to compare the bioequivalence of the test formulation to the reference product. Bioequivalence was determined based on the confidence intervals for the major pharmacokinetic parameters, AUC0-72 and Cmax, for donepezil.