Chitosan, a biopolymer derived from chitin, has garnered significant interest in the cosmetic industry due to its biocompatibility, biodegradability, and photoprotective properties. These features make it a key ingredient for developing innovative products that not only enhance cosmetic functionality but also address the growing demand for sustainability by reducing our reliance on fossil-based resources. In this context, the present study investigates the use of chitosan in the encapsulation of antioxidants through microspheres designed to optimize the stability, bioactivity, and efficacy of antioxidant compounds against oxidative stress.

Microspheres were synthesized using advanced techniques such as spray drying, ensuring high reproducibility and adherence to sustainability standards. The microspheres were characterized through spectroscopy and thermal and chemical stability assays, confirming their capacity to protect the encapsulated active compounds. Subsequently, the microspheres were incorporated into cosmetic formulations containing at least 95% natural ingredients, aligning with current ecological cosmetic regulations. In vitro assays on human keratinocyte and fibroblast models were performed to evaluate the safety, stability, and antioxidant efficacy of these formulations.

The characterization of chitosan was optimized to evaluate its physicochemical properties, such as molecular weight, degree of deacetylation, and density, which are critical for its encapsulation efficiency and functionality in cosmetic formulations. After this, the results indicated that certain chitosan-based microspheres functioned as effective physical filters in keratinocytes, providing relevant photoprotective properties. In fibroblasts, the microspheres demonstrated an ability to mitigate UVA-induced cellular damage and reduce the generation of reactive oxygen species (ROS), a key marker of oxidative stress. These findings highlight the potential of chitosan not only as an encapsulating material but also as a multifunctional ingredient in advanced cosmetic formulations. Its ability to combine sustainability with innovation positions it as a promising solution for a constantly evolving cosmetic sector, addressing consumer demands and environmental regulations.