Ghaleb A. Husseini

Over the past few decades, notable advancements have been made in the field of transdermal drug delivery systems (TDDSs), presenting a promising alternative to conventional oral drug administration. This comprehensive review aims to enhance understanding of this method by examining various transdermal techniques, the skin’s role as a barrier to TDDS, factors affecting skin diffusion, and current challenges in TDDSs. The primary focus of this analysis centers on TDDSs utilizing hydrogels. A thorough exploration of hydrogel fundamentals, encompassing structure, properties, and synthesis, is provided to underscore the importance of hydrogels as carriers in transdermal drug delivery. The concluding section delves into strategies for hydrogel-based drug delivery, addressing challenges and exploring future directions.