Portable semisolid extrusion device for the production of personalized medicines in diverse settings

Abstract

The potential of 3D printing (3DP) in personalized medicine has led to the development of various pharmaceutical-grade printers, advancing its integration into clinical practice. However, accessible and decentralized solutions are still required to enable on-demand drug production in remote or resource-limited settings. Handheld 3D pens offer a compact, portable, and energy-efficient alternative, particularly suited for small pharmacies, mobile clinics, emergency operations, and underserved regions. This study presents the first application of a handheld 3D pen using semisolid extrusion (SSE) technology for the precise fabrication of citrulline lozenges (200–700 mg). Citrulline, an amino acid used in the treatment of rare diseases, was formulated into two pharma-ink bars containing 30 % and 50 % w/w citrulline. Minimal materials were used, with isomalt, a sugar substitute, as the main excipient along with water, and no organic solvents were involved. Dose personalization was evaluated by selecting the printed area and the printing time, with a strong correlation observed between printing time and final dose. The printed lozenges exhibited excellent dose accuracy and recovery (∼100 %), while dissolution tests reported an 80 % of citrulline released within the first 12 min. The pharma-ink bars remained stable over one month, exhibiting minimal water loss (∼2%) and retaining both printability and drug integrity. These findings establish handheld 3D pens as environmentally-friendly technology for rapid personalized drug manufacturing. The combination of stable pharma-inks and precise dose control underscores its potential for decentralized, on-demand production of personalized therapies in remote and resource-constrained environments.