Microarray patches for transdermal drug delivery: a critical narrative review of technological innovations, CMC challenges, clinical translation, and global health implementation

Microarray patches (MAPs), alternatively known as microneedle patches, is a paradigm shift in the administration of pharmaceutical agents and vaccines. By utilising micron-scale projections to breach the stratum corneum, MAPs bridge the gap between the convenience of transdermal patches and the efficacy of hypodermic injections. This critical narrative review synthesises advances in MAP technology for transdermal drug delivery, focusing on technological innovations, chemistry, manufacturing, and control (CMC) challenges, clinical translation, regulatory considerations, and global health implementation. Special emphasis is placed on CMC challenges, including sterilisation and stability profiling, as well as the landscape of Clinical Trials, highlighting recent frameworks for pivotal Phase III studies in measles and rubella. We conclude by evaluating the programmatic suitability of MAPs for low- and middle-income countries (LMICs), addressing critical barriers such as cold-chain logistics and trypanophobia. A coordinated evolution from product-by-product model to platform-industrialisation model involving vaccine, polymer and device producing companies, regulators, global-health agencies including World health organization (WHO), and technology enablers is necessary. The Measles-Rubella programme provides an important template. MAPs’ value is not about replacing a syringe but enabling equitable distribution of vaccination; a strategy to make vaccination less dependent on infrastructure. As scientific innovations, upscaling, unified regulatory frameworks and equitable access advance, MAPs will achieve global relevance.