Formulation and Evaluation of Sustained-Release Floating Tablets of Bupropion and Naltrexone

Abstract

Bupropion and Naltrexone are medications with significant therapeutic importance in treating depression and alcohol dependence, respectively. However, both drugs face challenges related to poor bioavailability and frequent dosing requirements due to their short half-lives and rapid first-pass metabolism. To overcome these limitations, this research work focused on developing and evaluating floating tablets containing a combination of Bupropion and Naltrexone using natural and synthetic polymers. The floating tablet formulations were prepared through granulation and compression methods, incorporating Xanthan gum and Hydroxypropyl Methylcellulose (HPMC) as polymer matrix systems along with sodium bicarbonate as a gas-generating agent. A total of ten formulation batches were developed, varying the polymer concentrations to study their effects on drug release patterns, buoyancy characteristics, and overall tablet performance. Pre-formulation studies, drug-excipient compatibility assessments, and comprehensive tablet evaluation including weight variation, hardness, friability, swelling behavior, floating duration, and in-vitro drug release studies were performed. Results demonstrated that formulations containing optimized polymer ratios exhibited excellent floating ability for more than 12 hours with controlled and sustained drug release following zero-order kinetics. The most promising formulations showed no sign of chemical interaction between the drugs and polymers, confirming their compatibility and suitability for pharmaceutical use. These findings suggest that the developed floating tablet formulations offer a promising approach for improving the therapeutic effectiveness of Bupropion and Naltrexone by prolonging their gastric residence time and providing sustained drug delivery.

Keywords: Bupropion, Naltrexone, floating tablets, gastro-retentive drug delivery, sustained release, bioavailability.