Journal de bioéquivalence et de biodisponibilité

Abstrait

Gabapentin Bioequivalence Study: Quantification by Liquid Chromatography Coupled to Mass Spectrometry

Eduardo Abib Junior, Luciana Fernandes Duarte, Renata Pereira, Joseane Montagner Pozzebon, Deo Tosetti and Juliana Marise Cardoso Custódio

The study was performed to compare the bioavailability of two gabapentin 400 mg capsule formulation (Gabapentin from Arrow Farmacêutica S/A as test formulation and Neurontin ® from Pfizer, Brazil, as reference formulation) in 26 volunteers of both sexes. The study was conducted open with randomized two period crossover design and a one week wash out period. Plasma samples were obtained over a 48 hour interval. The gabapentin was analyzed by LC/MS/MS, in the presence of pracetamole as internal standard. With plasma concentration vs. time curves, data obtained from this metabolite, the following pharmacokinetics parameters were obtained: AUC 0-t , AUC 0-inf and C max . Geometric mean of gabapentin/Neurontin ® 400 mg individual percent ratio was 100.58% AUC 0-t , 101.35% for AUC 0-inf and 97.76% for C max . The 90% confidence intervals were 92.00 – 109.95%, 93.00 – 110.44%, 88.41 – 108.10%, respectively. Since the 90% confidence intervals for C max , AUC 0-t and AUC 0 -inf were within the 80 – 125% interval proposed by Food and Drug Administration, it was concluded that gabapentin 400 mg capsule was bioequivalent to Neurontin ® 400 mg capsule according to both the rate and extent of absorption.