Advanced 3D Printed Microneedles and Transdermal Patch Systems in Pharmaceutical Additive Manufacturing

Transdermal drug delivery has gained sustained attention as one of the non-invasive unconventional to the oral and the injectable routes. The conventional patches, which have offered the controlled release; however, where it has faced the limitations in delivering the macromolecules across the skin barrier. The emergence of 3D printing has introduced an adaptable platform for a fabricating the microneedles and the transdermal patches with the precise geometrical control and the patient-specific customization. The pharmaceutical sector has explored additive manufacturing that has enabled the structural complexity and the dose personalization. Despite the technological progress, the conventional fabrication techniques, which have lacked reproducibility and the micro-scale precision. The limited drug loading capacity and the mechanical instability of microneedles, which have restricted the broader clinical translation. In addition, the scalability of the production process and the regulatory standardization have remained to be challenging in the additive manufacturing environment. This study has examined extrusion-based and the stereolithography-based 3D printing approaches that have the fabricated polymeric microneedle arrays and the layered transdermal patches. Biocompatible polymers, such as polyvinyl alcohol and the polylactic acid are selected for the formulation that have allowed structural integrity. Mechanical strength, and the release kinetics are evaluated through the in vitro skin models that have simulated the human epidermal conditions. Morphological characterization is performed using the scanning electron microscopy that has confirmed the dimensional accuracy. The fabricated microneedles, which have shown uniform geometry and the fracture force of 0.45 N. This performs better than the conventional methods. Drug-loaded patches achieve 96% loading uniformity and the insertion efficiency of 88%.