3D printed drug products: Non-destructive dose verification using a rapid point-and-shoot approach

Three-dimensional printing (3DP) has the potential to cause a paradigm shift in the manufacture of pharmaceuticals, enabling personalised medicines to be produced on-demand. To facilitate integration into healthcare, non-destructive characterisation techniques are required to ensure final product quality. Here, the use of process analytical technologies (PAT), including near infrared spectroscopy (NIR) and Raman confocal microscopy, were evaluated on paracetamol-loaded 3D printed cylindrical tablets composed of an acrylic polymer (Eudragit L100-55). Using a portable NIR spectrometer, a calibration model was developed, which predicted successfully drug concentration across the range of 4-40% w/w. The model demonstrated excellent linearity (R² = 0.996) and accuracy (RMSEP = 0.63%) and results were confirmed with conventional HPLC analysis. The model maintained high accuracy for tablets of a different geometry (torus shapes), a different formulation type (oral films) and when the polymer was changed from acrylic to cellulosic (hypromellose, HPMC). Raman confocal microscopy showed a homogenous drug distribution, with paracetamol predominantly present in the amorphous form as a solid dispersion. Overall, this article is the first to report the use of a rapid 'point-and-shoot' approach as a non-destructive quality control method, supporting the integration of 3DP for medicine production into clinical practice.