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This study explores the incorporation of 10% 3-O-ethyl L-ascorbic acid (ETVC), a derivative of vitamin C, into two lipid gel systems: a hydrogel (HG) consisting exclusively of lipids and water and a bigel (BG) combining the hydrogel with an oleogel made from olive oil and beeswax. We investigated the ETVC release profiles from both materials using synthetic membranes and measured their permeation through porcine skin in vitro. Additionally, the interaction of these lipid gel systems with the stratum corneum (SC) was determined. Results from the release study indicate that the BG exhibited slower ETVC release compared to the HG. The permeation experiments showed that the presence of lipids in the formulations enhanced ETVC retention in the skin. The HG delivered a higher amount to the SC, while the BG achieved greater retention in the epidermis. This difference is attributed to the different lipophilic nature of each material. The structural analysis of SC lipids revealed that the organization of surface lipids remained unaltered by the application of the gels. Finally, an in vitro efficacy test in porcine skin using methylene blue indicated that our ETVC gels exhibited antioxidant activity. These findings provide valuable insights into the potential of lipid-based gels for topical applications.

Ascorbic acid (AA) has many health benefits, including immune and cardiovascular deficiency protection, prenatal problems, and skin diseases. Unfortunately, AA is easily oxidized and has limited bioavailability. Thus, the development of formulations that stabilize and enhance the efficacy of AA is a challenge. In this study, 4% AA was encapsulated in two recently developed gels, a hydrogel and a bigel. The hydrogel was formed exclusively with lipids and water, and the bigel was a combination of the hydrogel with an oleogel formed with olive oil and beeswax. The effect of AA in gel microstructures was determined using X-ray scattering, rheology, and texture analysis. Additionally, the capacity of these materials to protect AA from degradation upon temperature and sunlight was studied. Results showed that the incorporation of AA into both materials did not affect their microstructure. Moreover, hydrogel-protected AA showed only 2% degradation after three months at 8 °C, while in aqueous solution, it degraded by 12%. Regarding sunlight, bigel showed a good shielding effect, exhibiting only 2% AA degradation after 22 h of exposure, whereas in aqueous solution, AA degraded by 10%. These results suggest that both proposed gels could be used in biomedical applications and the field of food.