Self-nanoemulsifying system in the accumulation of resveratrol and N-acetylcysteine in the epidermis and dermis

Trans-resveratrol (RES) and N-acetylcysteine (NAC) have protective effects on biological processes; therefore, they are frequently included in food supplements. Their possible applications for the prevention of free radical-induced damage to the skin are of particular physiological relevance; however, their usefulness is limited by their metabolic fate and the unpredictability of their delivery to the skin following oral administration. In this work, we evaluated the concomitant and direct application of RES and NAC on the skin using a self-nanoemulsifying system we previously developed for the oral delivery of poorly absorbed food supplements. We evaluated the capability of this system to increase RES and NAC accumulation in porcine skin using permeation studies in Franz diffusion cells. The ascorbyl palmitate (ASP) self-nanoemulsifying system considerably increased RES and NAC accumulation in the epidermis and dermis, which peaked 6 h after application. This study reveals a new formulation strategy to improve the bioavailability of ingredients, which was previously used in the health supplements field, but has rarely been employed in dermatology because of its poor distribution in the skin.