Opensource semi-solid 3D printer designed for oral drug production in hospital pharmacies

Three-dimensional (3D) printing is a manufacturing technique with a growing interest in drug production, especially via semi-solid extrusion (SSE) where a material lying between a solid and a liquid is deposited to create the desired form. However, accessibility to SSE 3D printer is limited. This study aimed to develop and validate a SSE 3D printer equipped with an in-process weighing system. As a proof-of-concept, vaseline and low acyl gellan gum containing levetiracetam (LVT) were used to validate the developed SSE 3D printer. The developed printer heated the content of 20 mL syringes to the desired temperature within 20 min. The weighing system was able to weigh the printlets continuously during 3D printing with a deviation of 0.3 to 0.5 % compared with an external analytical balance. The 3D printer produced vaseline printlets with a proportionality between mass and volume (R² 0.9954) and with repeatability over 3 days (RSD 1,5%). It was able to produce 30 LVT printlets complying with the European Pharmacopeia for content uniformity (EP 2.9.40) with an average content of 143.9 mg (RSD 1.2 %) and an acceptance value of 5.7. This customizable and affordable SSE 3D printer with its own local network is promising for the democratization of personalized medicine in hospital pharmacies.