Nanovesicles for transdermal drug delivery

The skin as an effective barrier makes drug penetration and permeation difficult, which limits the efficiency of drug delivery through the skin. There are several strategies including "chemical" and "physical" methods to improve the permeation of active substances through the skin for local or systemic drug delivery. Among the penetration enhancement methods, nanovesicles have been one of the popular and well-studied approaches for delivering drug to deeper layers of the skin or even systemic circulation. To overcome the poor permeability of drugs, innovative vesicular systems were developed including deformable liposomal systems such as invasomes, Transfersomes, ethosomes, etc., and nonlipid building blocks vesicular nanostructures such as niosomes. Polysomes have demonstrated encouraging results in delivering small molecules and large proteins to the skin. In the current review, we provide an overview of different vesicular nanostructures for transdermal drug delivery and their skin penetration mechanisms. Also, it is necessary to recognize the concepts of numerous vesicular systems and analyze their drawbacks and advantages. A deep analysis of these factors is expected to provide new insights and new avenues of exploration for research in this field, which may help vesicular formulations to enter the market in the near future.