Progressive cavity pump 3D printing system for pharmaceutical semi-solid drug printing

Semi-solid extrusion (SSE) 3D printing represents a versatile manufacturing approach for pharmaceutical dosage forms. To ensure reproducible Critical Quality Attributes (CQAs) of pharmaceutical dosage forms, printing systems must provide accurate, precise, and reproducible material deposition under dynamic material flow occurring during intermittent G-code-controlled printing. A progressive cavity pump (PCP)-based extrusion system allows responsive and reproducible material delivery through direct volumetric flow control. By establishing an open-source control interface between a retrofitted printing system and a commercial PCP, an adaptable and cost-effective pharmaceutical 3D printing platform was developed. The 3D printer achieved the desired volumetric accuracy and responsiveness across various dynamic G-code-controlled extrusion profiles, without being affected by transient material flow conditions, showing excellent accuracy ranging between 99.6 % and 100.1 %. The improved extrusion control contributed to achieving the desired CQAs of the pharmaceutical printlets, particularly by ensuring consistent printlet mass, as reflected by the very low mass variation of 0.2%. In addition, high deposition accuracy was confirmed by the close agreement between the measured and predefined CAD dimensions, with RSDs of 0.6% and 1.0% for diameter and height, respectively. Overall, the system provides a cost-effective and freely adaptable pharmaceutical SSE 3D printing system with advanced extrusion control.