In this work, we utilize skin penetration enhancers (SPEs) such as ceramide and fatty acids in lipid nanovesicles to promote the transdermal delivery of active ingredients. These SPE-incorporated lipid nanovesicles (SPE-LNV) interact with the constituents of skin's outermost stratum corneum (SC) layer, enabling even niacinamide and adenosine with high water solubility to effectively permeate through, leading to enhanced skin efficacy. We demonstrate by both in vitro and in vivo skin permeation studies that the SPE-LNV formulation containing both ceramide and fatty acids (LNV-CF) exhibits deeper penetration depth and faster permeation rate compared to conventional lipid nanovesicles (LNV) without SPE as well as LNV-C with only ceramide. Moreover, in vivo clinical trials were also performed to confirm that LNV-CF most effectively mediates the delivery of niacinamide and adenosine, resulting in a substantial decrease in melanin index as well as skin wrinkle compared to the control groups. We envision that the strategy of incorporating both ceramide and fatty acids in lipid nanovesicles offers a simple and convenient route for the rapid and effective delivery of water-soluble active ingredients across the skin barrier layer.
Keywords: adenosine; ceramides; fatty acids; lipid nanovesicles; niacinamide; skin penetration enhancers.