Stabilization and release profile of retinol and tocopherol with microcapsules based on chitosan

The incorporation of unstable cosmetic actives such as retinol into formulations requires methods of stabilization to ensure their long-term activity and efficacy. A delivery system entrapping lipophilic vitamins such as retinol and tocopherol based on chitosan coacervation with negative polymers is described in this paper. The microcapsules appear to be spherical with a narrow particle size distribution, not aggregated, and with a homogeneous surface. Microencapsulation with such a system prolongs the active's life in skin care O/W formulations by at least one order of magnitude in the tested formulas. Furthermore, the biodegradation profile of this delivery system is consistent with a sustained release profile in human epidermis.