Physical Methods for Topical Skin Drug Delivery: Concepts and Applications

The document from 2018 reviews advancements in topical drug delivery, particularly focusing on overcoming the skin's stratum corneum barrier using physical methods such as iontophoresis, sonophoresis, and microneedles. Iontophoresis uses electrical currents to enhance drug permeation, especially for macromolecules, while sonophoresis employs low-frequency ultrasound to increase skin permeability. Microneedles create microscopic channels in the skin to dramatically increase drug penetration without causing pain. The document also discusses the use of these methods in various treatments, including skin cancer, alopecia, and atopic dermatitis, and highlights the potential of combining physical methods with chemical enhancers to further improve drug delivery. Clinical trials and studies are mentioned, including one with over 40 patients showing the effectiveness of iontophoresis-assisted therapy for actinic keratosis and another with 120 participants using low-frequency ultrasound for chronic wounds. The document concludes that these physical methods are promising for enhancing drug delivery in dermatological applications.