Evaluation of skin permeability of resveratrol loaded liposomes and nanostructured lipid carriers using a Skin Mimic Artificial Membrane (skin-PAMPA)

Background: The skin-PAMPA test is a quick and relatively deep tool in the early stages of drug discovery and formulation of dermal and transdermal delivery systems. Objective: This study focused on the application of the skin-PAMPA test to evaluate the permeation of resveratrol (RSV) and also of two formulations, liposomes (LP) and nanostructured lipid carriers (NLC), prepared to improve RSV topical delivery. Methods: LP and NLC were physically and chemically characterized. Stability and in vitro release studies were also assessed in different pH media. The release results were applied to define the kinetic and mechanism of RSV release from the LP and NLC formulations. In vitro permeability was estimated through the skin-PAMPA and the antioxidant capacity was evaluated by DPPH test. Results: Nanoparticles have a spherical shape, dimensions suitable for skin application, and narrow size distribution. Encapsulation efficiency was 96.5% ± 2.1 for LP and 86.00% ± 2.37 for NLC. The formu- lations increased RSV solubility. Nanoparticles showed excellent physical and chemical stability during storage at 4 °C for two months. In vitro release studies were performed at pH 5.5 and 7.4. The nanopar- ticles achieved a prolonged release of RSV. Skin-PAMPA proved an increased cutaneous permeability of RSV when loaded into LP or NLC. Both formulations maintained the antioxidant capacity of RSV, as evidenced by DPPH test. Conclusion: LP and NLC could be applied as drug delivery systems suitable for the topical delivery of the RSV. Skin-PAMPA has proved to be an effective tool for studying the permeability not only of the RSV but also of its formulations.