Modification of Prednisolone Acetate Release from Monolithic 3D-Printed Systems: The Role of Formulation Composition and Process Parameters

Background/Objectives: A major advantage of 3D printing technology is the ability to modify drug release by adjusting formulation composition and printing parameters. The aim of this study was to develop and characterize 3D-printed tablets containing prednisolone acetate and to investigate the effects of formulation composition and printing parameters, namely infill density and pattern, on the drug release profile. Methods: Filaments composed of polyvinyl alcohol, sorbitol, and prednisolone acetate, with sodium alginate incorporated in selected formulations, were prepared using hot melt extrusion. The obtained filaments were characterized and used for the fabrication of tablets via fused deposition modeling. The resulting tablets were evaluated in terms of mass variation, dimensions, hardness, content uniformity and drug release rate. Results: The extrusion of polyvinyl alcohol and prednisolone acetate in the absence of additional excipients resulted in a defective filament, highlighting the need for sorbitol incorporation. In contrast, all other filament formulations (F2–F4) exhibited a uniform structure and homogeneous drug distribution. The 3D-printed tablets complied with pharmacopeial requirements for mass variation and content uniformity and demonstrated good precision and reproducibility in terms of dimensions and hardness. Lower infill density was associated with faster drug release, while the presence of sodium alginate resulted in slower release, particularly at higher infill percentages and with a gyroid infill pattern. Furthermore, formulations with higher sorbitol content demonstrated an increased release rate of prednisolone acetate. Conclusions: Infill density was identified as the dominant factor affecting release kinetics. Among the tested formulations, A100G (gyroid structure with 100% infill density), containing prednisolone acetate, polyvinyl alcohol, sorbitol, and sodium alginate, proved most suitable for achieving sustained drug release.