Design, Formulation and Evaluation of Fixed-Dose Combination of Telmisartan and Metformin Hydrochloride Filled in Hard Gelatin Capsules

Abstract

Background: Hypertension and type 2 diabetes mellitus are chronic diseases that frequently coexist, sharing overlapping pathophysiological mechanisms and risk factors. Their simultaneous presence significantly increases cardiovascular complications, necessitating effective combination therapy.

Methods: The present study was undertaken to design, formulate, and evaluate a fixed-dose combination capsule containing immediate-release Telmisartan granules and sustained-release Metformin hydrochloride pellets. Metformin pellets were prepared using suitable release-retarding polymers to achieve controlled drug release, while Telmisartan granules were formulated with appropriate disintegrants and excipients to ensure rapid onset of action. The prepared pellets and granules were evaluated for pre-formulation and post-formulation parameters, including particle size distribution, flow properties, friability, drug content, disintegration, and dissolution. Optimized formulations were filled into hard gelatin capsules using a manual capsule filling method and further assessed for capsule quality parameters such as weight variation, content uniformity, disintegration time, and drug release characteristics.

Results: Both pellets and granules exhibited satisfactory physicochemical properties and complied with pharmacopeial standards. Dissolution studies confirmed sustained drug release of Metformin over an extended period, while Telmisartan demonstrated rapid release consistent with immediate-release requirements. Capsule evaluation parameters, including weight variation and physical integrity, were within acceptable limits, confirming the suitability of the formulation for oral administration.

Conclusion: The developed pellet-granule filled capsule system successfully achieved the intended release characteristics of both drugs. This novel dosage form offers improved patient convenience, reduced pill burden, and enhanced therapeutic efficacy in the simultaneous management of hypertension and type 2 diabetes mellitus.