Fatty acids based α-Tocopherol loaded nanostructured lipid carrier gel: In vitro and in vivo evaluation for moisturizing and anti-aging effects

Background alpha-Tocopherol is a potent antioxidant present in the skin. Its concentration decreases with age. Synthetically available alpha-tocopherol is viscous, irritating to skin and unstable toward oxidation and ultraviolet (UV) light. Aims To develop fatty acids based nanostructured lipid carrier (NLC) gel loaded with alpha-tocopherol and to evaluate its moisturizing and anti-aging properties. Methods Lauric acid, oleic acid, and Tween-80 were used as solid lipid, liquid lipid, and surfactant, respectively. Seven formulations (F0-F6) were developed by using different concentration of ingredients. Most optimized formulation (F2) was selected for further study on the basis of characterization. Dialysis tube method was used for release study. F2 was incorporated in gel, and then, in vitro and noninvasive in vivo study regarding skin moisture content by corneometer(R)and skin mechanical properties by cutometer(R)for 12 weeks on human volunteers (n = 13) was conducted. Results Size, polydispersibility index (PDI), zeta potential, and %entrapment efficiency (%EE) of optimized formulation (F2) were found 82 nm, 0.261, -28.6, and 94.88 +/- 1.16, respectively. Particles were spherical in shape. The release profile showed initial burst and then sustained release, and release data were best fitted to weibull model. alpha-tocopherol loaded NLC gel (NLCG) appeared physically stable for 12 weeks at room temperature and showed significant results in terms of skin capacitance and mechanical properties. Rheological assessment showed non-Newtonian behavior. Conclusion Fatty acids based NLC proved to be a promising carrier of photochemically unstable lipophilic vitamin E with enhanced moisturizing and anti-aging properties.