Anti-Aging Evaluation of Cosmetics on a Tri-Layered Chitosan Membrane: An Alternative to Animal Testing

The search for alternatives to animal testing in cosmetics has encouraged the development of in vitro systems capable of evaluating formulation-driven biophysical parameters assessed on human skin. This study presents a cell-free tri-layered chitosan membrane as a material-based model for characterizing the physicochemical anti-aging performance of topical formulations. Three cosmetic products were incorporated either in the top layer (1L(t)) or across all layers (3L), and key parameters—including pore area, water permeation, firmness, elasticity, swelling and moisture retention—were quantified. VitCOil produced consistent effects across configurations, reducing pore area by 52–56% and decreasing water permeation by 54–61%, while increasing moisture retention by 36–38%. OilSerum showed a marked layer-dependent response, enhancing swelling by +70% in 3L and +35% in 1L(t), and increasing water permeation by 16% (3L) and 4% (1L(t)). EyeCr improved firmness and elasticity at low concentration, with stronger elastic response in the top layer (+27% in 3L; +34% in 1L(t)). Overall, this novel platform strengthens early-stage physicochemical screening by linking formulation-dependent mechanisms with directional biophysical trends observed clinically.