Development of a 3D Printing Liquid Crystal Display (LCD)-Assisted Micromolding Methodology for Custom Fabrication of Polymeric Microneedles Using Experimental Design

<b>Background/Objectives</b>: Polymeric microneedles are an innovative drug delivery form combining the benefits of both transdermal and intravenous administration. However, their practical application is limited by fabrication challenges. To address this, the study explores a novel approach for the rapid, precise, and customized production of polymeric microneedles of diverse geometries by utilizing Liquid Crystal Display (LCD) 3D printing technology, marking the first reported use of this technique for microneedle mold fabrication. <b>Methods</b>: LCD 3D printing technology was applied to prepare resin biocompatible microneedle molds. The method developed was optimized by identifying and controlling the critical process parameters (CPPs) through implementing statistical experimental design techniques within the Quality by Design regulatory framework for pharmaceutical development. The optimized molds were subsequently utilized to produce polyvinyl alcohol microneedles with customized shapes and geometries. Representative designs were then loaded with Ropinirole Hydrochloride as a model drug and evaluated in relation to their morphology, drug content, skin insertion depth, and permeability. <b>Results</b>: The application of a Central Composite Design identified layer height and exposure time as the critical process parameters affecting mold fabrication. The optimized design space enabled the selection of printing conditions that maximized dimensional accuracy. Employing these optimum LCD 3D printing parameters, microneedles of various shapes and dimensions were successfully fabricated, exhibiting highly dimensional accuracy. Additionally, tuning skin permeability was proven to be feasible by adjusting microneedle geometry. <b>Conclusions</b>: This work demonstrates the successful use of LCD 3D printing technology in producing biocompatible molds for customized microneedle fabrication, facilitating the development of transdermal delivery systems with personalized drug permeation profiles.