A tunable extruded 3D printing platform using thermo-sensitive pastes.

Extruded 3D printing is emerging as an attractive fabrication technology in the field of personalized oral medicines. The objective of this study was to develop a tunable extruded 3D printing platform based on thermo-sensitive gelatin pastes to meet the needs of achieving different drug release characteristics with flexible dosing and design. The printability and mechanisms of extrusion and deposition of the gelatin pastes were systematically studied. Ibuprofen and diclofenac sodium were used as model drugs for immediate- and sustained-release formulations, respectively. Following the optimization of formulation and process parameters, ibuprofen immediate-release formulations with different designs, and reservoir-type diclofenac sodium sustained-release formulations were printed. Target drug release patterns were successfully obtained for both model drugs. Rheological studies revealed that additives such as microcrystalline cellulose and hydroxypropyl methylcellulose can act as both thickeners and proppants of gelatin matrix. Furthermore, computational fluid dynamics simulation was used to visualize the printing process, and quantitatively analyze the influence of material viscosity, inlet velocity and nozzle diameter on the pressure and velocity of extrusion flow field. The present study demonstrated the great potential of extruded 3D printing technology using the thermo-sensitive gelatin paste platform for personalized oral medicines.