Development and Evaluation of Prolonged Release Carvedilol Matrix Tablets Using Hydrophilic–Hydrophobic Polymer Blends

Objective: The present work was aimed at designing and optimizing a prolonged-release matrix tablet of carvedilol (12.5 mg) employing binary polymer combinations to achieve sustained antihypertensive and cardioprotective action over 24 hours and improve patient compliance through once-daily dosing. Methods: Nine formulations (F1–F9) were developed via wet granulation using varying proportions of hydroxypropyl methylcellulose (HPMC) K100M and ethyl cellulose (EC) N50 as rate-controlling polymers. Preformulation studies including Fourier-transform infrared (FTIR) spectroscopy were conducted to evaluate drug–excipient compatibility. The micromeritic properties of granules and physicomechanical characteristics of compressed tablets were assessed. In vitro drug release was performed in pH 6.8 phosphate buffer using a USP Type II dissolution apparatus at 37 ± 0.5 °C and 50 rpm. Dissolution kinetics were analyzed by zero-order, first-order, Higuchi, Korsmeyer–Peppas, and Hixson–Crowell models. Accelerated stability studies were conducted as per ICH Q1A(R2) guidelines. Results: Compatibility studies confirmed the absence of physicochemical interactions between carvedilol and the selected excipients. Among all developed batches, formulation F5, containing 20% w/w HPMC K100M and 5% w/w ethyl cellulose N50, exhibited the most desirable dissolution profile, releasing 95.5 ± 1.1 % of the drug over a 24-hour period. The release followed near-zero-order kinetics (R² = 0.981) with an anomalous (non-Fickian) transport mechanism (release exponent, n = 0.52; R² = 0.991). All formulations complied with pharmacopeial limits for weight variation, hardness, friability, and content uniformity. Accelerated stability testing (40 ± 2 °C / 75 ± 5 % RH, 90 days) demonstrated no significant change in drug content or release behaviour; the similarity factor (f₂) remained above 83. Conclusion: The optimized prolonged-release matrix tablet successfully sustained carvedilol release over 24 hours and displayed excellent physicochemical stability, presenting a viable platform for once-daily oral administration in the management of essential hypertension and chronic heart failure.