3D-PRINTED FLOATING DRUG DELIVERY SYSTEMS: PRINCIPLES, TECHNOLOGIES, FORMULATION STRATEGIES AND FUTURE PERSPECTIVES

Abstract Floating drug delivery systems (FDDS) are gastroretentive oral dosage forms designed to remain buoyant in the stomach and prolong gastric residence. They are particularly useful for drugs with a narrow absorption window in the upper gastrointestinal tract, limited intestinal solubility, short biological half-life, or a requirement for local gastric action. However, conventional FDDS are influenced by gastric physiology, fixed dosage designs, limited dose flexibility, and manufacturing challenges Three-dimensional (3D) printing is an additive manufacturing technology that enables precise control over dosage-form geometry, internal architecture, porosity, density, drug loading, and drug-release characteristics. This review discusses the principles and classification of FDDS and explores their integration with 3D printing. Major pharmaceutical printing techniques, including fused deposition modelling (FDM), semi-solid extrusion (SSE), selective laser sintering (SLS), thermal inkjet printing, and binder jetting, are reviewed with emphasis on their applicability to gastroretentive systems. 3D-printed gastroretentive systems have demonstrated rapid buoyancy, prolonged and controlled drug release, customized dosage-form geometry, and the potential for patient-specific dosing. These approaches provide greater flexibility in designing floating systems compared with conventional manufacturing methods. Despite these advantages, challenges related to printable materials, thermal or solvent exposure, drug-loading capacity, dimensional accuracy, scale-up, quality control, reproducibility, and regulatory requirements remain. Advances in pharmaceutical materials, digital design, process monitoring, and predictive modelling may facilitate the translation of 3D-printed FDDS into personalized oral drug delivery. Keywords: 3D printing; additive manufacturing; floating drug delivery system; gastroretentive drug delivery; personalized medicine