Integration of Nanocarriers and Microneedles for Enhanced Transdermal Drug Delivery: Current Advances and Future Perspectives

Transdermal drug delivery systems (TDDS) are a non-invasive route of administration that can allow drugs to reach tissues underneath the skin. Some of the benefits of TDDS include their ability to avoid first-pass metabolism, provide a sustained drug release, and improve patient compliance. However, drug permeation through the skin is limited by the stratum corneum, which acts as a strong barrier to permeation, particularly for hydrophilic and high MW drugs. Nanotechnology-based systems (e.g. liposomes, nanoparticles, nano emulsions) have been developed to improve stability, permeability, and targeted delivery of the drug; however, the intact skin barrier limits their effectiveness. Microneedles offer a physical enhancement strategy for drug delivery; by creating microchannels in the skin, microneedles enable effective and painless transport of the drug. Combining nanoformulations with microneedles produces a synergistic effect, increasing the permeation of drugs into the body, the bioavailability of medications, and controlling the release of both. This makes it possible to administer a diverse range of drugs, such as proteins, peptides, vaccines, and insulin. Using nanoformulations in conjunction with microneedles results in improved therapeutic performance and increases the potential of such systems to be used for hormonal therapies, vaccinations, diabetes treatment, and cosmetic systems. As technological advancements continue to occur within the areas of smart nanocarriers and stimuli-responsive systems, the possibilities for such systems to improve precision and efficiency will only continue to increase. Therefore, the nano-microneedle combinations represent an innovative approach in contemporary pharmaceutical sciences for next generation, user friendly drug delivery.