Transdermal Drug Delivery Systems in Atopic Dermatitis: A Review of Vehicle Innovation and Skin Barrier Challenges

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin condition marked by immune dysregulation, pruritus, and impaired skin barrier function. Effective transdermal drug delivery is essential for therapeutic success but remains hindered by stratum corneum (SC) dysfunction and variable skin permeability. This review examines recent advancements in vehicle formulations designed to enhance transdermal drug delivery, specifically in the context of AD. Peer-reviewed studies published within the last two decades were reviewed using PubMed and Google Scholar (Google LLC, Mountain View, California, United States), focusing on innovations in drug delivery systems, vehicle composition, and clinical applications. Novel delivery platforms such as liposomes, ethosomes, nanoemulsions, polymeric nanoparticles, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs) have demonstrated improved percutaneous absorption, increased drug stability, and reduced skin irritation. Additional breakthroughs include biomimetic formulations, occlusive enhancers, and pH-sensitive carriers tailored to the disrupted skin barrier in AD. Despite these advancements, significant challenges remain, including variability in skin hydration, interindividual differences in barrier function, and concerns about long-term safety. Continued research and clinical trials are necessary to validate the efficacy and tolerability of these technologies. Future advances may lie in personalizing transdermal therapies through skin barrier phenotyping, enabling more targeted, tolerable, and effective treatment strategies.