Formulation development and evaluation of sustained release gastroretentive tablet of emtricitabine

Abstract

Objective: The study aims for the design and evaluation of floating tablets of emtricitabine (EMT), post oral administration to sustain the release and enhance gastric residence time (GRT). Methods: EMT is a nucleoside reverse-transcriptase inhibitor for the prevention and treatment of human immunodeficiency virus (HIV) infection. The investigation was considered to formulate a floating tablet of EMT with various agents. The formulation included with various concentrations of hydroxypropyl methylcellulose (HPMC) k4m, ethylcellulose, microcrystalline cellulose, polyvinylpyrrolidone (PVP) by wet granulation method. Various parameters for the prepared formulations were evaluated for weight variation, thickness, hardness, friability, floating lag time (FLT), total floating time (TFT), swelling index, in vitro drug release, and fourier-transform infrared spectroscopy (FTIR) studies. Results: The best formulation F1 exhibited 88.28% release in 24 h duration, with a floating lag time of 7 min and swelling index of 52.1% and drug content was determined to be 98.27%. The release mechanism was determined to be first order with higuchi release kinetics displaying diffusion along with the dissolution of the EMT from the tablet by non fickian mechanism. Conclusion: EMT tablets showed an increased GRT with a sustained release for 24 h thereby allowing a better window for absorption consequently improve the therapeutic effect of the drug.