Investigation on hot melt extrusion and prediction on 3D printability of pharmaceutical grade polymers

The development of printable filaments has been identified as a critical aspect for the processing of pharmaceutical grade polymers and the fabrication of oral solid dosage forms. In this study a range of plain and drug loaded polymers were investigated and assessed for their printability in comparison to commercial filaments. Physicochemical characterizations of the polymers included differential scanning calorimetry (DSC) thermogravimetric analysis (TGA) and rheology were studied prior to Hot Melt Extrusion processing for the filament fabrication. A texture analyser was used to study the filament mechanical properties in order to derive the maximum tensile strength, Young's Modulus and elongation at break. Principal component analysis was used to compare the printability of the polymer and to identify the contribution of each mechanical property. The analysis showed that maximum tensile strength with a threshold between 15 and 20 MPa is the most critical property for the prediction of the printability. Furthermore, printable filaments were processed using Fusion Deposition Modelling technology and optimal printing parameters were identified. The study demonstrated that the prediction of filament printability is feasible by evaluating the mechanical properties.