Floating-Mucoadhesive Gastro-Retentive Tablets for Enhanced Oral Delivery of Glimepiride: Formulation, Optimization,...

Glimepiride (GLM), an essential sulfonylurea for type 2 diabetes management, suffers from poor solubility, variable absorption, and a narrow upper-GI absorption window, resulting in inconsistent therapeutic outcomes. To overcome these limitations, floating-mucoadhesive (FM) gastro-retentive tablets were developed using HPMC K15M, Carbopol 940P, and sodium bicarbonate to achieve prolonged gastric retention and controlled intragastric drug release. A 3² factorial design was employed to optimize polymer composition and effervescent loading, yielding an optimized formulation with rapid buoyancy and uninterrupted flotation for more than 24 h. Physicochemical evaluation (FTIR, DSC) confirmed drug-excipient compatibility, while pre and post-compression analyses verified acceptable mechanical and micromeritic characteristics. In-vitro studies demonstrated sustained GLM release for 6 h, following Higuchi kinetics with Fickian diffusion, supported by stable swelling dynamics and moderate mucoadhesive strength. Scanning electron microscopy further elucidated the release mechanism by revealing time-dependent matrix swelling, pore formation, and internal structural evolution during dissolution, corroborating diffusion-controlled drug transport. The optimized system exhibited in-vitro attributes indicative of prolonged gastric retention and controlled drug release, suggesting its potential to improve the oral bioavailability of GLM. This formulation approach may be extended to other drugs requiring localized gastric retention and diffusion-modulated release.