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.