3D-Printed Modular Static Franz Diffusion Cells Holder for Transdermal Drug Delivery Studies

Franz diffusion cells represent a cornerstone tool for studying in vitro transdermal delivery of drugs in pharmaceutical, cosmetic, and biomedical research. Commercially available multi-cell heating and stirring systems are expensive ($5,000–$20,000) and lack flexibility for modification or teaching purposes. To overcome these limitations, we designed and validated a low-cost, open-source, 3D-printed Modular Static Franz Diffusion Cells Holder (6-FDCH). The device integrates three custom-printed components within a PVC housing, featuring spray-foam insulation and an embedded heating bath to ensure thermal stability. A central threaded bolt and wing nut mechanism secure donor and receiver chambers, while foam inserts maintain consistent alignment and reproducibility across experiments. The system accommodates six Franz diffusion cells simultaneously, providing uniform positioning relative to a magnetic stirrer. Costing under $185, the 6-FDCH offers substantial savings, reduces assembly complexity, and facilitates routine cleaning. Its open-source, parameterized design in OpenSCAD enables broad customization and dissemination, enhancing accessibility for resource-limited laboratories. By combining affordability, reproducibility, and adaptability, this platform advances high-quality transdermal and diffusion research, supports undergraduate training, and promotes open science practices in biomedical hardware development.