Recent Advances in Electronic Skin Technologies for Transdermal Drug Delivery Applications

Transdermal drug delivery systems (TDDS) represent an effective and widely adopted approach to drug administration due to several advantages over conventional delivery methods. These benefits include sustained and controlled drug release, avoidance of first-pass hepatic metabolism, and improved patient compliance. Despite these advantages, the skin acts as a complex and highly protective barrier composed of multiple layers that a drug must traverse to reach systemic circulation, with limited skin permeability remaining a major challenge. The successful design of TDDS depends on careful consideration of drug-related properties such as molecular weight, solubility, and lipophilicity, as well as formulation factors and skin characteristics including hydration, temperature, and site-specific permeability. To overcome the barrier function of the stratum corneum, chemical permeation enhancers are commonly employed to disrupt its lipid matrix. In addition, natural permeation enhancers, such as essential oils and terpenes, have emerged as promising alternatives due to their efficacy and biocompatibility. Recent advancements in electronic skin (e-skin) technologies, based on flexible and conductive polymers, have demonstrated significant potential as versatile platforms for transdermal drug delivery. The integration of sensors and electronic components into e-skin devices enables real-time monitoring of skin health parameters, including temperature, hydration, and pH. Moreover, e-skin systems offer opportunities for precise and controlled drug delivery through techniques such as iontophoresis. This paper reviews the current state of e-skin technology with a focus on its applications in transdermal drug delivery and skin disease management, while also highlighting future prospects and key challenges in this rapidly evolving field.