Fabrication of Gastroretentive and Extended-Release Famotidine Floating Tablets via Fused Deposition Modeling

Famotidine suffers from low oral bioavailability due to poor aqueous solubility, short half-life, and limited gastric retention. This study aimed to develop gastro-retentive floating tablets of famotidine using hot-melt extrusion (HME) and fused deposition modeling (FDM) 3D printing approach to enhance its solubility, prolong gastric residence, and achieve extended drug release. Famotidine was incorporated into various polymeric carriers, including hydroxypropyl cellulose (HPC LF) and hydroxypropyl methylcellulose (HPMC E5), to produce drug-loaded filaments using an 11 mm twin-screw co-rotating extruder. The filaments were subsequently 3D-printed into low-density, hollow tablets to achieve prolonged gastric floatation. The solid-state characterization by differential scanning calorimetry (DSC) revealed the absence of famotidine's crystalline melting peak in both filaments and 3D-printed tablets, suggesting amorphization within the polymer matrix. FTIR spectroscopy indicated hydrogen bonding interactions between famotidine and polymer hydroxyl groups, supporting the stabilization of the solid dispersion. The lead formulation demonstrated excellent buoyancy of about nine hours and extended drug release in 0.1 N HCl, confirming the potential of the system for extended gastric retention. This work highlights the utility of HME-FDM 3D printing for developing tailored, gastro-retentive dosage forms that enhance the performance of poorly soluble drugs like famotidine through amorphous solid dispersion and formulation-driven design.