Continuous 3D printing of medicines via a directly coupled twin-screw hot-melt extrusion printing system

3D printing drug formulations for personalized medicine is a growing research field and offers many opportunities to improve patient therapy. Downsides of pharmaceutical 3D printing include increased manufacturing costs, lower throughput, potentially high production temperatures, or a lack of suitable excipients. This is especially true for fused deposition modeling, a melt-based technology that involves two heating steps: hot-melt extrusion of the intermediate feedstock material and the actual printing process. This study presents a solution to this issue, the integrated HME3D system consisting of a twin-screw extruder directly coupled with a 3D printing system. This allows the creation of solid dosage forms directly from the extrusion process. The print head is connected to the extruder and enables printing on a conveyor-belt. Four materials, two polymers and two lipid excipients, were processed, printed, and evaluated for mass consistency. To one polymer and one lipid, ritonavir was added to assess content uniformity. Additionally, a solid lipid-based formulation (sLBF) was printed with the HME3D system and compared to 3D printed sLBFs from two semisolid extrusion (SSE) systems. Mass and content uniformity were best for the HME3D system, and the dissolution profiles of the sLBF printed via the HME3D system show smaller fluctuation within the first 8 hours of release compared to the SSE printed samples. This study successfully demonstrates the capabilities of a directly coupled twin-screw extrusion-3D printing system and expands the excipient space to previously unprintable materials, such as conventional solid lipids.