Comparative Dissolution Study of Enzalutamide Capsules in India

Abstract

Introduction: The objective was to conduct a comparative dissolution study of several brands of enzalutamide capsules available in the Indian market using a model-independent approach. Enzalutamide is classified as a Biopharmaceutical Classification System class 2 medicine due to its limited solubility in water and high ability to pass through the intestines. Methods: A United States Pharmacopeia apparatus 2 (paddle) was used with 0.3% cetyl trimethyl ammonium bromide (CTAB) in 0.1 N HCl as dissolution medium at 37.0 ± 0.5 °C and 50 rpm to provide the most favorable conditions for testing. Four generic brands of enzalutamide capsules were compared to the reference brand product. Because the focus was mostly on the model-independent technique, a concurrent study of the model-dependent strategy was conducted for comparison. Results: The Weibull model provided the most optimal fit for all brands. For every brand, the difference factor (f1) and cumulative drug release were within the acceptable range. However, generic brand 2 failed to meet the acceptance criteria for the similarity factor (f2) and difference in dissolution efficiency. Generic brand 4 was the most similar to the reference product based on the model-independent approach. Conclusion: Three out of four generic products were found to be interchangeable with the reference product, and generic product 4 is the preferred generic substitution for ENZ capsules in India.