Transdermal needle-free drug delivery approaches and activation mechanism

The evolution of transdermal drug delivery (TDD) systems has transformed non-invasive drug delivery by improving safety, precision, and patient compliance. While conventional TDD methods face challenges with penetration efficiency and dosage control, needle-free transdermal drug delivery technologies are emerging as a promising alternative. This review critically examines recent advancements in transdermal needle-free drug delivery technologies, focusing on different physical penetration methods and activation mechanisms such as spring-based, gas-driven, electrochemical, piezoelectric, laser-induced and electromagnetic approaches, which generate sufficient force for increasing the penetration ability of the drugs through the stratum corneum. The paper also discusses the implications of these technologies for wearable and personalised healthcare, highlighting future directions for clinical translation and real-world deployment.