Microneedles (MNs) - A versatile transdermal drug delivery system: Types, Fabrication Methodology, Release Mechanism, Evaluation Parameters, Biological Application and Clinical Case Studies

Because of the limitations of the oral drug delivery system, as well as the discomfort associated with the usage of needles in the case of injections, drug delivery research has shifted significantly toward the transdermal route of administration. Topical creams, gels, and transdermal patches are the most often utilised means of transdermal administration of drugs. Since the stratum corneum layer of the skin acts as a barrier to a drug molecule, the effect of the majority of therapeutic agents is limited. As a result, only a small number of molecules are able to reach the site of action. A new type of delivery method, known as microneedles, is being developed to improve the distribution of drugs through this route while also overcoming the various issues associated with existing formulations. Non-invasive and painless feature of microneedles have making them ideal for self-administration. This review describes various type of microneedles and their design, fabrication methodology, various materials used in fabrication of microneedles, drug release mechanism from the microneedles, evaluation parameters, it’s biological application, update about recent clinical studies and in last, challenges and future perspective of microneedles as drug delivery system.