FORMULATION AND CHARACTERIZATION OF FLOATING SUSTAINED RELEASE TABLETS OF NEFOPAM HYDROCHLORIDE

Abstract

The present study was aimed at formulating and evaluating floating sustained release tablets of Nefopam Hydrochloride to prolong gastric residence time and achieve controlled drug release, thereby improving therapeutic efficacy and patient compliance. Nine formulations (F1–F9) were prepared using varying concentrations of hydrophilic polymers such as HPMC K15M and Carbopol 934, along with sodium bicarbonate as a gas-generating agent. Pre-compression and post-compression evaluations were conducted to assess powder flow, hardness, friability, drug content, and floating properties. In-vitro buoyancy and drug release studies were performed using USP dissolution apparatus. The release data were fitted to various kinetic models to determine the mechanism of drug release. All formulations showed acceptable pre-compression properties with good flowability. Post-compression results confirmed uniform weight, acceptable hardness (6.3–6.8 kg/cm²), low friability (<1%), and high drug content (96.45%–99.25%). All tablets exhibited floating lag times below 65 seconds and total floating durations exceeding 12 hours. Among the formulations, F7 showed optimal performance with a cumulative drug release of 99.01% at 12 hours, and followed first-order release kinetics (R² = 0.9665), indicating a concentration-dependent release mechanism. The Peppas model (R² = 0.9332) suggested anomalous transport as the drug release mechanism. The optimized formulation (F7) successfully achieved sustained drug release and prolonged gastric retention, making it a promising candidate for once-daily oral therapy of Nefopam Hydrochloride.