Development and Characterization of Pharmaceutical-Grade Eudragit® L100 Filaments for FDM 3D Printing of Solid Oral Dosage Forms

Fused Deposition Modeling (FDM) three-dimensional printing is an emerging technology in pharmaceutical technology, offering significant opportunities for treatment personalization and precise control of drug release profiles. However, one of the major technological limitations remains the availability of filaments specifically designed for pharmaceutical applications, as an alternative to conventional plastic polymers such as PLA or ABS. The present study aims to develop pharmaceutical-grade filaments suitable for FDM 3D printing using authorized excipients, and to evaluate their physicochemical and biopharmaceutical properties. Formulations based on Eudragit® L100, plasticized with glycerin or butyl phthalate, were prepared by extrusion using a semi-artisanal shaping process. The resulting filaments were characterized in terms of appearance, hardness, mechanical resistance to breakage, and drug release profiles of two model compounds, methylene blue and ibuprofen, in simulated gastrointestinal media. The results demonstrate that Eudragit® L100 enables the production of filaments exhibiting a satisfactory balance between rigidity and flexibility, compatible with FDM 3D printing requirements. Release studies revealed a preferential drug release in simulated intestinal medium, confirming the pH-dependent behavior of the polymer. These findings demonstrate the feasibility of developing functional pharmaceutical filaments and highlight the potential of additive manufacturing for the production of personalized oral dosage forms. Keywords: Pharmaceutical 3D printing; Fused Deposition Modeling (FDM); pharmaceutical filaments; Eudragit® L100; pH-dependent drug release.