Desenvolvimento e caracterização de um comprimido flutuante à base de argila montmorilonita e HPMC para liberação prolongada

Introduction: Floating tablets consist of low-density systems that can float in the gastric contents, by air entrapment action, either with air chambers or effervescent agents, remaining longer in the stomach allowing a prolonged release profile. The combination of clays and polymers in the development of new drug delivery systems is very useful as it improves mechanical properties, stability, resistance to solvents or gases, improves surface properties and biocompatibility. Objective: Development and characterization of an effervescent floating system for prolonged release, based on HPMC and Montmorillonite clay. Methods: The tablets were manufactured by wet granulation and characterized by pharmacopoeial tests including in vitro release studies using metformin as a model drug. Results: Using a Taguchi design, 4 formulations of floating tablets with release times of 8 to 24 h were obtained. Formulations 2 and 4 met USP extended-release requirements. It was observed that the combination of HPMC and Montmorillonite favored prolonged release through gel formation and increased tortuosity. Conclusions: Four formulations of extended-release effervescent floating tablets were obtained. The combination of Montmorillonite clay and HPMC had an impact on the structural and barrier properties (tortuosity) to control release, which depends on the ratio used in the polymer-clay combination and its ability to stabilize the gel structure.