In vitro bioequivalence of pregabalin capsules (150 mg): An alternative to in vivo bioequivalence studies

Abstract

Introduction: We aimed to study the dissolution behavior of available brands of pregabalin in the United Arab Emirates (UAE) (Ras Al Khaimah) market and to report efficiency and fungibility data for generic brands under biowaiver conditions. Methods: The pharmaceutical parameters of five brands of pregabalin 150 mg capsules were analyzed, including the reference product and four generic products. Dissolution tests were performed as per WHO and FDA recommendations (pH 1.2, 4.5, and 6.8). United States Pharmacopeia (USP) apparatus 2 (paddle, 50 rpm) was used to assess drug release. Multiple time points were measured to estimate the drug release profile of the capsules. Pharmacokinetic models and similarity factor analysis were performed. Results: The percentage of drug release within 15 minutes was 95–102% at pH 1.2, 86–95% at pH 4.5, and 89–98% at pH 6.8. Different kinetic models were used to analyze the suitability level of drug release from the different capsules. In all the three buffers, first order kinetics and the Korsmeyer–Peppas model demonstrated the drug release with R2 ≥ 0.95, which helps to predict and evaluate the acceptability level of drug release. The similarity and difference factor results were within the acceptable range for all capsules. Conclusion: The dissolution profiles of all tested capsules of pregabalin in the UAE market are pharmaceutically and therapeutically equivalent. The results indicate that the post-market analysis is essential for determining interchangeability of different brands of the same drug.