3D printing technology in microneedles: An emerging era in transdermal drug delivery

3D printing technology in microneedle (MN) is revolutionizing the transdermal drug-delivery field. This review introduces 3D printing to MN fabrication and its potential to enhance drug delivery efficiency, thereby overcoming issues of earlier methods. Transdermal drug delivery system (TDDS) offers many advantages, remarkably non-invasive delivery with greater patient compliance, by eliminating problems such as first-pass metabolism and gastrointestinal degradation. MNs are minimally invasive devices designed to penetrate the stratum corneum, thus enabling the delivery of various therapeutic agents, including vaccines and biologics. The review separates MNs into several types: solid, coated, hollow, and dissolving, with their characteristic features and applications. 3D printing enables the exact customization of MNs in shape, size, and drug loading capacity, allowing for tailor-made treatments for individual patients. Additionally, 3D-printed MNs offer advantages such as rapid prototyping, complex structural designs, and precise control over drug release, making them highly promising for clinical applications. On the other hand, some challenges remain, such as manufacturing speed limitations and questions about product quality and intellectual property issues. Future advancements in 3D printing materials, automation, and scalable production techniques are expected to overcome these limitations, paving the way for broader adoption. This review also discusses the wide range of applications involving 3D-printed MNs, such as biosensing, cancer treatment, and chronic disease management. It is this synthesis, therefore, that finally underlines the very promise of 3D printing in MN technology towards a revolutionary form of drug delivery in the creation of a future of personalized medicine, overcoming important challenges within current pharmaceutical practice.