Design and Evaluation of Hydrophilic Polymer-Based Matrix Tablets for Extended Release of Metoprolol Succinate: A Comparative Study of Natural and Synthetic Polymers

Abstract

Purpose:
The objective of this study was to design and evaluate extended-release (ER) matrix tablets of Metoprolol Succinate using natural and synthetic hydrophilic polymers. The study aimed to compare the effect of polymer type and concentration on physicochemical properties, drug-release behavior, and release kinetics.

Methods:
Matrix tablets were prepared using natural polymers (guar gum, xanthan gum) and synthetic polymers (HPMC K4M, HPMC K15M, Carbopol) via direct compression and wet granulation. Preformulation studies including FTIR and DSC were performed to assess drug–excipient compatibility. Powder blend flow properties and post-compression parameters were evaluated according to pharmacopeial standards. In-vitro dissolution was performed using USP Apparatus II in 0.1 N HCl and phosphate buffer pH 6.8. Drug-release data were fitted to zero-order, first-order, Higuchi, and Korsmeyer–Peppas models to determine kinetics and mechanism.