A Review on Microneedle-Assisted Transdermal Drug Delivery: Revolutionizing Non-Invasive Therapy

Transdermal drug delivery mediated by microneedles represents an innovative method for the delivery of therapeutic agents through the skin. The use of microneedles creates microscopic and temporary pathways through the stratum corneum and overcomes the primary hurdle of transdermal drug delivery, thereby enhancing the delivery of drugs to the systemic circulation. Microneedles provide a non-invasive, pain-free and convenient mode of drug delivery compared to hypodermic needles. Several categories of microneedles such as solid microneedles, coated microneedles, hollow microneedles, dissolving microneedles, hydrogel-forming microneedles, and bio-responsive microneedles have been designed for addressing various pharmaceutical and clinical objectives. The development in fabrication technologies, materials used, and drug delivery strategies has led to a wide range of applications of microneedles in delivering vaccines, insulin, hormones, proteins, peptides, nucleic acids, and anti-cancer agents. Significant advantages have been achieved using microneedle-mediated systems in infectious disease therapy, diabetic management, dermatological conditions, cancer treatments, and cosmetic applications. In spite of issues involving manufacturing scale-up, loading capacity, stability, and approval by health authorities, continuous advancements like smart microneedles, wearable devices, incorporation of nanotechnology, and AI-based designs have kept the field evolving. Microneedle technology overall is a promising delivery platform for the future of minimally invasive treatments and personalized medicine.