(310a) Mitigating Challenges of Eudragit L100-55 for Semi-Solid Extrusion 3D Printing

Eudragit L100-55, a pH-responsive anionic copolymer suitable for intestinal drug delivery with a pH above 5.5. The semi-solid extrusion (SSE) 3D printing of Eudragit L100-55 presents significant challenges, particularly due to its tackiness, rapid evaporation of volatile solvent causing premature solidification during printing, and requiring suitable rheological properties. In this research, an attempt was made to overcome all these challenges and make Eudragit L100-55 suitable for SSE 3D printing. An ink formulation was developed using Eudragit L100-55 and additional functional excipients to overcome the challenges. To address the solvent volatility issue, NMP (N-Methyl-2-pyrrolidone) was initially used as a solvent in place of the acetone/methanol mixture; however, NMP's high boiling point hindered the successful drying of 3D prints at the preferred drying temperature. As a solution, ethanol was introduced as a solvent, offering greater control by minimizing solvent evaporation and enabling proper drying of successful 3D prints. Furthermore, Glycerol Monostearate (GMS) was incorporated to reduce the tackiness of the polymer in solution, while Xanthan Gum (XG) was added to enhance rheological properties, ensuring adequate rheology of the ink. Triethyl Citrate (TEC), a non-toxic, biodegradable plasticizer, was selected for smooth and consistent extrusion. These strategic optimizations effectively address the key challenges associated with the 3D printing of Eudragit L100-55. This study demonstrates the potential of adapting Eudragit L100-55 for SSE 3D printing applications, laying the foundation for customizable, pH-responsive drug delivery systems designed for targeted therapeutics.