Delving deeper into dermal and transdermal drug delivery: Factors and mechanisms associated with nanocarrier-mediated strategies

Background: Advances in material science and particle engineering have led to the development of a rapidly growing number of nanoparticulate carriers for drug and gene delivery. These carriers are increasingly being investigated in dermal and transdermal routes of drug administration. Objective: To critically examine and summarize the primary factors and mechanisms involved in nanocarrier-mediated dermal and transdermal delivery of drugs. Method: Thorough literature search was undertaken, spanning the early development of nanocarrier-mediated dermal and transdermal drug delivery approaches, to the current state of the art, using online search tools. Results: Physicochemical, formulation, experimental and morphological factors, such as, material of construction or type of nanoparticle (NP), surface chemistry, particle size, particle shape, surface charge, dispersion medium, duration of exposure of skin to NPs, combination of NPs with physical agents, and aspects related to skin were identified and discussed. Conclusion: The key factors and mechanisms which influence NPs-skin interactions in dermal and transdermal drug delivery are discussed in this article in-line with the current advances in the field.