Matrix-Based Sustained Release Formulations of Metformin Hydrochloride: Current Trends and Evaluation Techniques

Metformin hydrochloride (MET) is an oral hypoglycemic agent which improves glucose tolerance in patients with type 2 diabetes and diminishes basal plasma levels of glucose. The aim of this study was to develop and optimize MET matrix tablets for SR application. The SR matrix tablet of MET was prepared by wet granulation technique using Polyvinyl pyrrolidone K30 and hydroxyl propyl methylcellulose of different viscosity grades (HPMC K4M, HPMC K15M, and HPMC K100M). The influence of varying the polymer ratios was evaluated. The excipients used in this study did not modify physicochemical properties of the drug. Sustained release (SR) formulations of metformin address the drug's short half-life, allowing for once-daily dosing and potentially better patient compliance compared to immediate-release (IR) forms. This review highlights the current trends in the formulation of matrix-based SR systems for Metformin HCl, focusing on the role of polymers, formulation strategies, and comprehensive evaluation techniques.