ABSTRACT
BACKGROUND: Brewers' spent grain (BSG) is one of the most abundant by-products of the beer industry and causes serious environmental problems. Ferulic acid (FA) is an antioxidant with potential cosmeceutical applications. FA was extracted from BSG, developing a method of high extraction performance in order to be encapsulated in ultradeformable liposomes (Nanoferulic, NF). AIMS: To obtain a product with high added value such as FA, from a residue currently underused, using simple and economical chemical methods. To load FA into a nanosystem designed for the topical route, its encapsulation has the purpose to take profit from its photoprotective, anti-inflammatory, and antioxidant properties in the deep layers of the skin. METHODS: Ferulic acid was obtained from dried BSG using acid and basic treatments in series. NF was prepared by lipid film resuspension of a solution containing FA obtained from BSG. Size and Z-potential were determined. Cytotoxicity was assessed in vitro. Skin penetration was assessed by NF determination at different skin depths and by confocal microscopy. RESULTS: The yield of the extraction process was 0.43% on a dry basis. Encapsulation rendered liposomes of around 140 nm with 92% of encapsulation efficiency. No toxicity was observed in all the tested concentrations. Successful results were obtained from the regeneration studies. CONCLUSIONS: It was possible to develop a nanosystem containing FA, generating a high-value commercial input for the pharmaceutical and cosmeceutical industry. The use of BSG generated in industrial scale would help to reduce the volume of highly polluting waste.
