Single-Dose, Randomized, Open-Label, Two-Way, Crossover Bioequivalence Study of Two Formulations of Pregabalin 300 mg Hard Capsules in Healthy Volunteers Under Fasting Conditions

AIMS: This bioequivalence study was conducted to assess the bioequivalence of two formulations, test and reference, of pregabalin 300 mg hard capsules, under fasting conditions. METHODS: This was a single-center, randomized, single-dose, open-label, laboratory-blinded, two-way crossover study, with a minimum washout period of 7 days. Plasma samples were collected prior to and up to 36 h after dosing. Pregabalin plasma concentrations were determined, using a validated method, by reversed phase high performance liquid chromatography coupled to a tandem mass spectrometry detector (LC–MS–MS). Pharmacokinetic metrics used for bioequivalence assessment were the AUC((0–t)) (area under the plasma concentration–time curve from time zero to time of last observed non-zero plasma concentration) and the C(max) (maximum observed plasma concentration). These parameters were determined from the pregabalin plasma concentration data using noncompartmental analysis. RESULTS: Forty healthy subjects, age ranging from 18 to 43 years old, were enrolled and randomized, of whom 39 completed the study. The ratio of geometric least square means for C(max) was 99.29 % (90 % confidence interval [CI] 93.29–105.67). The ratio of geometric least square means for AUC((0–t)) was 101.54 % (90 % CI 100.13–102.98). The 90 % CIs were within the predefined range (80.00–125.00). CONCLUSIONS: Bioequivalence between test and reference formulations, under fasting conditions, was concluded both in terms of rate and extent of absorption.