A novel 3D printing enabled method for fast and reliable construction of polymeric microneedles using experimental design

In the last decades, there is a growing need for novel dosage forms which are easily administrated and consequently facilitate patient compliance. Microneedles, although being an intriguing approach, have not been studied extensively due to their complex fabrication process. The aim of the present study was the application of FDM 3D printing technology to simplify microneedle production by direct preparation of negative molds. The method developed was optimized by identifying and controlling the critical process parameters via implementing statistical experimental design techniques. Layer height, path width and their interaction were the factors affecting 3D printing process. 3D printed molds were then used to prepare PVA/PVP microneedles with Galantamine hydrobromide as API. Fabricated arrays were characterized and the release profile of the API, in relation to the microneedles composition, was examined. %PVA, drug loading and their interaction were found statistically significant in controlling the release profile of Galantamine via the Strat-M (R) artificial membrane. The results of this design enabled the selection of the formulation with maximum release, for further ex vivo evaluation of the API's permeability through the skin, which proved the feasibility of this novel microneedle development for enhanced transdermal delivery.