Volumetric 3D printing for rapid production of medicines

3D printing (3DP), or additive manufacturing, has been actively investigated as one of the enabling technologies for the impending era of personalized medicines. However, existing 3DP technologies do not afford the speeds required for on-demand production of medicines in fast-paced clinical settings. Volumetric printing is a novel 3DP technology that offers rapid printing speed and overcomes the geometric and surface quality limitations of layer-based vat photopolymerization techniques. Unlike previous vat photopolymerization 3DP technologies, volumetric printing cures the entire desired 3D geometry simultaneously by exploiting the threshold behavior in the photopolymerization process that arise due to oxygen-induced polymerization inhibition. In this work, for the first time, a volumetric printer was used to fabricate drug-loaded 3D printed tablets (Printlets™) within seconds. Six resin formulations were evaluated using this printer, each composed of poly(ethylene glycol) diacrylate (PEGDA) as the crosslinking monomer, lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) as the photoinitiator, and paracetamol as the model drug. Water or PEG300 were included as diluents in varying concentrations to facilitate drug release. Paracetamol-loaded Printlets were successfully fabricated within 17 s. Drug release rates could be tuned by altering the monomer-to-diluent ratio of the photosensitive resin, with a lower ratio releasing drug faster. The present work confirms the suitability of volumetric 3DP for printing drug products in a matter of seconds. Upon further optimization, this novel technology can enable rapid, on-demand fabrication of medicines and medical devices.