Skin Tolerability of Oleic Acid Based Nanovesicles Designed for the Improvement of Icariin and Naproxen Percutaneous Permeation

Deformable nanovesicles have a crucial role in topical drug delivery through the skin, due to their capability to pass intact the stratum corneum and epidermis (SCE) and significantly increase the efficacy and accumulation of payloads in the deeper layers of the skin. Namely, lipid-based ultradeformable nanovesicles are versatile and load bioactive molecules with different physicochemical properties. For this reason, this study aims to make oleic acid based nanovesicles (oleosomes) for the codelivery of icariin and sodium naproxen and increase their permeation through the skin. Oleosomes have suitable physicochemical properties and long-term stability for a potential dermal or transdermal application. The inclusion of oleic acid in the lipid bilayer increases 3-fold the deformable properties of oleosomes compared to conventional liposomes and significantly improves the percutaneous permeation of icariin and sodium naproxen through the human SCE membranes compared to hydroalcoholic solutions of both drugs. The tolerability studies on human volunteers demonstrate that oleosomes are safer and speed up the recovery of transepidermal water loss (TEWL) baselines compared to saline solution. These results highlight promising properties of icariin/sodium naproxen coloaded oleosomes for the treatment of skin disorders and suggest the potential future applications of these nanovesicles for further in vivo experiments.