Objectives <p>3D-printing technology enables the manufacturing of personalised medication tailored to patients’ medical needs. Through semisolid extrusion, 3D-printed tablets can be produced with precise dosages, allowing for customisation across various medications. Achieving this, however, requires careful consideration and optimisation of multiple factors related to 3D printing, including pharmaceutical formulation, printer settings, and tablet dimensions. This research develops 3D-printed Mexiletine HCl tablets for the treatment of Nondystrophic myotonia.</p> Significance <p>Eutectic system-based formulations are introduced to 3D drug printing and employed to develop the first 3D-printed Mexiletine HCl Tablets.</p> Methods <p>Eutectic system-based formulations were designed and further optimised to ensure desired tablet characteristics including hardness, durability, and texture. Tablet size was then adjusted to deliver up to 200&#xa0;mg per tablet, with High-Performance Liquid Chromatography (HPLC) analysis employed to confirm the active pharmaceutical ingredient (API) content.</p> Results <p>The Mexiletine HCl formulations were developed by combining Monolaurin with either a sugar alcohol (e.g., Sorbitol, Xylitol) or a polymer (e.g., Polyvinyl pyrrolidone (PVP), Polyethylene glycol (PEG) 35,000) and were further optimized with Tween 80 to enhance formulation properties. The incorporation of Tween 80 improved the flow properties of the semisolid formulation, resulting in a higher success rate for tablet printing, and a marked reduction in the required printing temperature. Notably, Xylitol-based formulations yielded robust tablets across different sizes, thanks to the rapid solidification of the material, which maintained the tablets’ shapes.</p> Conclusions <p>Through systematic screening of excipients and printer settings, this study developed eutectic system-based Mexiletine HCl tablets, ensuring process quality and consistency.</p>