Comparison of fused-filament fabrication to direct compression and injection molding in the manufacture of oral tablets

Oral tablets are a convenient form to deliver active pharmaceutical ingredients (API) and have a high level of acceptance from clinicians and patients. There is a wide range of excipients available for the fabrication of tablets thereby offering a versatile platform for the delivery of therapeutic agents to the gastrointestinal tract. However, the geometry of tablets is limited by conventional manufacturing processes. This study aimed to compare three manufacturing processes in the production of flat-faced oral tablets using the same formulation composed of a polymer blend and caffeine as a model drug: fused-filament fabrication (FFF), direct compression (DC) and injection molding (IM). Hot-melt extrusion was used to convert a powder blend into feedstock material for FFF and IM processes, while DC was performed on the powder mixture. Tablets were produced with the same dimensions and were characterised for their physical and dissolution properties. There were statistical differences in the physical properties and drug release profiles of the tablets produced by the different manufacturing processes. DC tablets displayed immediate release, IM provided
sustained release over 48 hours, and FFF tablets displayed both release types depending on the printing parameters. FFF continues to demonstrate high potential as a manufacturing process for the efficient production of personalized oral tablets.