Isabela Costa César, Ricardo Martins Duarte Byrro, Fabiana Fernandes de Santana e Silva, Leonardo de Souza Teixeira, Fernanda Crunivel de Abreu and Gerson Antônio Pianetti
The bioequivalence of a single dose of memantine (Clomenac®) 10 mg tablets manufactured by Cobalt Pharmaceuticals, Canada/Arrow Farmacêutica Ltda was compared with a reference memantine 10 mg tablets (Ebix®, Lundbeck Inc). The single-dose, randomized-sequence, open-label, two period crossover study was conducted on a total of 26 Brazilian healthy volunteers of both genders. Nineteen blood samples were taken during 72 h. Samples were frozen and kept until time of analysis. Plasma concentrations of memantine were determined using a validated UPLC-MS/MS method. Confidence intervals (CI, 90%) for the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC0-t) were determined by calculating log-transformed data. The test and reference formulations were considered bioequivalent if the 90% CIs for the geometric mean test/reference ratios were within a predetermined range of 80% to 125%. The 90% CI for the geometric mean ratios for Cmax was 100.1% (92.9- 107.9%) and for AUC0-t was 98.8% (93.9-103.9%). In conclusion, the tested 10 mg memantine tablets (Clomenac®, Arrow Farmacêutica Ltda.) was bioequivalent to Ebix® 10 mg tablets, according to the rate and extent of absorption.