Design and characterization of a novel 3D printed pressure-controlled drug delivery system

The aim of the present work was to explore the feasibility of 3D printing via fused deposition modeling (FDM) in the manufacturing of a pressure-controlled drug delivery system. Eudragit (R) RS, a brittle polymer with pH-independent solubility, was chosen to be a suitable excipient for the 3D printing of a pressure-sensitive, capsule-like dosage form. A self-constructed piston extruder was used for hot melt extrusion (HME) of filaments made from Eudragit (R) RS that could be used for 3D printing. Subsequently, the printing parameters were experimentally optimized with the aid of a self-programmed software. This G-code generator allowed the simple adjustment of printing speed, temperature, extrusion multiplier and layer height. By this, capsule-shaped dosage forms with the desired mechanical properties could be obtained. The effect of physiological pressure events on the drug release behaviour from the novel dosage form was finally tested by using a biorelevant stress test device. These in vitro experiments demonstrated the rapid and quantitative release of the probe drug after applying realistic pressure events. This work illustrated that 3D printing can be an interesting technique for the production of pressure-controlled dosage forms as a new concept of oral drug delivery.