Expanding the pharmaceutical formulation space in material extrusion 3D printing applications

The two major drawbacks of filament based material extrusion printing in pharmaceutical manufacturing are a) the additional manufacturing step of the filament prior to printing and b) the limited pharmaceutical formulation space due to unsuitable (mechanical and rheological) properties. Although formulation strategies can address some of these issues, they require heavily formulated or complex systems, which require time and resource to solve/overcome. In this study we present a novel, filament free 3D printing system, obviating limitations of unsuitable filament properties and opening up the pharmaceutical formulation space in material extrusion of pharmaceutical oral solid dose forms (OSDs). Prasad et al. reported on a 30% w/w Paracetamol (PCM) in Affinisol™ HPMC HME 15LV (30PCM-AFF) formulation, not printable on a conventional filament based material extrusion printer. This formulation was processed on the filament free 3D printer to successfully print OSDs. In initial rheological screening tests, process conditions for initial printing trials were identified. The operating space of the filament free 3D printer and slicer settings in this process were investigated as well as the uniformity of mass and dimensions of printed OSDs. A relationship of Slicer Infill percentage (microstructure) and tablet core weight was also assessed, demonstrating the ability to create patient centred dose forms. Material reconciliation showed good traceability of material during the manufacturing process.