Formulation and Evaluation of Carbamazepine Floating Matrix Sustained-Release Tablets Using Psyllium Husk Approach for Sustained Immunosuppression in Rheumatoid Arthritis

Abstract

The present study aimed to formulate and evaluate effervescent floating matrix sustained-release tablets of carbamazepine using Eudragit L-100 and psyllium husk as matrix-forming materials. Gastro-retentive floating systems are designed to remain buoyant in gastric contents and release drug over an extended period, potentially supporting delivery to the upper gastrointestinal tract. Five formulations (F1–F5) were prepared by direct compression. Sodium bicarbonate and citric acid were incorporated as gas-generating components, while microcrystalline cellulose, talc and magnesium stearate served as formulation auxiliaries. Powder blends were assessed for flow-related parameters, and the compressed tablets were evaluated for physical quality, drug content, buoyancy, swelling, in-vitro release and drug–excipient compatibility. The source study reports a carbamazepine absorption maximum (λmax) of 283 nm in 0.1 N hydrochloric acid and linearity over 5–20 μg/mL. Drug content across the formulations ranged from 97.18% to 100.4%. Formulation F4 showed a reported buoyancy lag time of 14 seconds, an 8-hour swelling index of 65.57%, and 97.86% drug release at 12 hours. FTIR and DSC observations were interpreted as indicating no significant interaction between carbamazepine and the selected polymers. Based on the reported in-vitro results, F4 was selected as the optimized formulation. Further confirmation, including reproducibility, stability and in-vivo evaluation, is needed before drawing clinical conclusions.