Dear Colleagues,

This Special Issue aims at focusing attention on the most modern formulation methods to direct the active ingredient at the site of action in or beyond the skin barrier for the treatment of localized or diffuse diseases. In the first case, we talk about topical administration with an effect on the surface of the skin or within the skin (epidermis and dermis) to treat cutaneous disorders or cutaneous manifestations of a general disease, also with cosmetic purposes; the second case refers to transdermal administration with a systemic effect. The skin can be considered a real organ covering the body, with different functions: Protective and barrier, sensorial, secretive, and temperature and blood pressure regulation. The extremely effective barrier effect against external substances, microorganisms, sunlight, heat, and electric current makes the skin difficult to penetrate and permeate. In fact, there are few molecules that easily permeate the cutaneous barrier, due to their chemical and physical characteristics. The formulation plays an essential role in the interaction between the active and the substrate and in reversibly modifying the permeability of the skin barrier.

In the last few years, research has focused on the development of particulate carriers as a new strategy to modulate the skin barrier and/or provide novel delivery systems for the active ingredient under study. Liposomes, solid lipid or polymeric nanoparticles (nanocapsules, nanosphere), niosomes, nanoemulsions, and nanomicelles belong to this category and, depending on the type of carrier chosen, allow the active ingredient to concentrate in the outermost skin layers or to be delivered more deeply in the skin strata, even when normal skin structure is altered due to different disorders. In addition to the intercellular route, which is the major penetration pathway, penetration through skin appendages (the shunt route) has gained renewed interest because it seems to be the predominant pathway for nanostructured delivery systems. Particulate carriers may facilitate active ingredient delivery by encapsulation of the molecules in order to increase drug localization into the hair follicles and keratinocytes in different layers of epidermis, and may provide depot into the skin through slow and sustained drug release.

Therefore, the aim of this Special issue is to provide an overview of the current knowledge in this field through original papers, reviews, and short communications.

Dr. Daniela Monti
Guest Editor

Manuscript Submission Information

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• Cutaneous penetration/distribution
• Particulate carriers
• Transdermal permeation
• Drug delivery
• Cosmetics
• Enhancers
• Topical formulations