Journal of Bioequivalence & Bioavailability

Abstract

Comparative Bioavailability of Two Quetiapine Formulations in Healthy Volunteers after a Single Dose Administration

Eduardo Abib Junior, Luciana Fernandes Duarte, Eunice Mayumi Suenaga, Alessandro de Carvalho Cruz and Clovis Ryuichi Nakaie

The study was performed to compare the bioavailability of two quetiapine 25 mg tablet formulations: the test formulation was quetiapine fumarate (kitapen®) manufactured by Cobalt Pharmaceuticals, Canada/ Arrow Farmacêutica Ltda* (Erowlabs). Seroquel® (quetiapine) from Astrazeneca Brazil was used as reference formulation. The study was conducted open with randomized two period crossover design and one week wash out period in 64 volunteers of both sexes. Plasma samples were obtained over a 48 hour interval. Quetiapine was analyzed by LC-MS-MS in the presence of quetiapine-D8 as internal standard. Plasma samples were obtained over a 48 hour interval. Quetiapine was analyzed by LC-MS-MS in the presence of quetiapine-D8 as internal standard. The mean ratio of parameters Cmax and AUC 0-t and 90% confidence intervals of correspondents were calculated to determine the bioequivalence. The means AUC 0-t for test and reference formulation were 432.41 ng.h/mL and 412.20 ng.h/mL, for AUC 0-∞ were 440.06 ng.h/mL and 418.90 ng.h/mL and, for Cmax 126.94 ng/mL and 108.71 ng/mL, respectively. Geometric mean of quetiapine (kitapen®)/Seroquel® 25 mg individual percent ratio was 97.68% AUC 0-t , 97.47% for AUC 0-∞ and 90.68% for C max . The 90% confidence intervals were 92.67 – 102.96%, 92.53 – 102.67%, 83.37 – 98.64%, respectively. Since the 90% confidence intervals for C max , AUC 0-t and AUC 0-∞ were within the 80 – 125% interval proposed by Food and Drug Administration, it was concluded that quetiapine (kitapen®) 25 mg tablet was bioequivalent to Seroquel® 25 mg tablet according to both the rate and extent of absorption.