Cyclodextrins as cosmetic delivery systems

Aim of this work was the study of ferulic acid/cyclodextrin (CD) association complexes. Ferulic acid (FA) is a compound well-known as antioxidant and photoprotective agent (approved in Japan as sunscreen). Notwithstanding this, it is poorly suited for cosmetic applications because it undergoes functional and organoleptic modifications, when it is exposed to air, UV-light and heat. For this reason we prepared a set of FA/CD complexes with the aim to improve its physico-chemical stability. The inclusion complexes were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and nuclear magnetic resonance (1H-NMR). The FA/alpha-CD complex showed the most promising properties (high association constant, high degree of photostability, slower FA release) as sunscreen delivery system.