Formulation of Caffeine–Hydroxypropyl-β-Cyclodextrin Complex in Hydrogel for Skin Treatment

Caffeine is a well-known xanthine that possesses antioxidant effects that could contribute to its application in different skin disorders. In order to enhance its effects, approaches for improving its permeation and penetration through skin layers could be applied. This study emphasizes the preparation of caffeine-cyclodextrin complex and its formulation in carbopol hydrogel. The complex was developed at a 1:1 molar ratio between caffeine and hydroxypropyl-β-cyclodextrin. It was found that the complex enhanced the radical scavenging activity of caffeine against ABTS radical as well as the protective effects against H₂O₂-induced oxidative stress in L929 fibroblasts. Then, the complex was formulated in hydrogel by applying 1% carbopol. The spreadability and penetration of the loaded hydrogel were improved in comparison with the empty hydrogel. The results revealed that the system could be appropriate for therapies of skin disorders, and its wound healing abilities could be further investigated.