Processability of poly(vinyl alcohol) Based Filaments With Paracetamol Prepared by Hot-Melt Extrusion for Additive Manufacturing

Abstract

The aim of this study was to evaluate the processability of poly(vinyl alcohol) (PVA)-based filaments containing paracetamol (PAR) prepared by hot-melt extrusion for fused deposition modelling (FDM) 3D printing, as function of drug content (0–50%w/w) and storage conditions (temperature: 20–40 °C and humidity: 11–75%). Thermal (DSC), crystallographic (XRPD), spectroscopic (FTIR), moisture content and mechanical tests were used to characterize the filaments, whereas their ability to produce tablets was confirmed by printing. XRPD revealed the absence of crystalline PAR in the extruded filaments with <30% PAR and FTIR confirmed interactions between PAR and PVA. Mechanical tests have shown a higher brittleness of the filaments with increasing PAR, making them non-printable. Throughout storage, temperature and moisture increased the plasticity of the filaments, which was reflected by changes on their thermal and mechanical properties improving the feeding performance on the printer. Filaments stored at low moisture remained unsuitable for printing with amorphous PAR being preserved. Dissolution tests have shown that the release of PAR from printed tablets was independent of the storage time of the filaments. The study highlights the need for optimized storage conditions of filaments for FDM and the dependency on the drug's content in such filaments.