Strategies for Enhancing (Trans)dermal Drug Delivery: Formulation Challenges and Emerging Trends

Systems for (trans)dermal drug delivery represent an important research area in pharmaceutical technology and one of the most widely developed classes of pharmaceutical formulations on the global market. Their use enables the overcoming of limitations associated with oral and parenteral drug administration, including low bioavailability and systemic side effects. However, human skin, particularly the stratum corneum, acts as a highly organized barrier that significantly restricts the penetration of active substances into and through the skin, making it difficult to achieve therapeutic concentrations at the site of action or in systemic circulation.

This monograph provides an overview of the theoretical principles of (trans)dermal drug delivery, including mechanisms of drug transport across the skin and factors influencing this process. Special emphasis is placed on passive and active strategies for enhancing permeation and overcoming the skin barrier. Different approaches are discussed in terms of composition, manufacturing methods, mechanisms of action, advantages, and limitations, along with representative experimental examples demonstrating their potential to enhance percutaneous drug transport.