Efficacy of a cosmetic formulation containing a blend of nanoencapsulated antioxidants by in vitro, ex-vivo and in vivo studies
Author: Samara Eberlin
Published at: December 01, 2022
32nd IFSCC Congress (International Federation of Societies of Cosmetic Chemists), London, 19-22 September, 2022.
Ana Paula Fonseca, Carine Dal Pizzol, Samara Eberlin, Antonio Carlos Vanzo, Patricia M. B. G. Maia Campos.
The application of antioxidants in cosmetic products contributing to collagen preservation and synthesis, acting in melanogenesis, and improving overall skin health and appearance is advancing. Thus, the objective of this study was to evaluate the efficacy and safety of a cosmetic formulation containing a blend of ingredients, such as nano ascorbyl palmitate, nano resveratrol, tocopherol, nano caffeine, carnosine, and niacinamide by ex vivo and clinical evaluations. The in vitro tests were performed through the measurement of mitochondrial reactive oxygen species (mROS) in human fibroblast cell culture after IR-A radiation and after IR-A plus treatment with the investigational product (IP). After the approval of the Ethics Committee, measurements of melanin, type 1 procollagen were performed in ex vivo human tissue from elective plastic surgery after UV radiation and after radiation plus the cosmetic treatment. In addition, filaggrin was also measured in ex vivo human tissue, but this time after skin barrier rupture with SLS 5% and after this rupture plus investigational product treatment. Finally, a clinical study was performed by instrumental measurements to evaluate skin hydration (Corneometer), skin oiliness (Sebumeter), collagen synthesis with diffuse reflection spectroscopy (DRS), and swelling around the eyes using the Vectra XT imaging system. For this, after the approval of the Ethics Committee, 20 healthy females aged 40 to 50 years old, Fitzpatrick phototype II, III, and IV were recruited. In addition, a self-assessment questionnaire was applied to evaluate perceived efficacy by study participants. Safety and tolerance studies were also carried out with the product under use, as well as acne lesions count on the skin by an investigator dermatologist. The in vitro study showed that the product statistically (p<0.001) decreased mROS by -73.13% at 10.01 mg/ml; -64.58% at 3.17 mg/ml and -59.88% at 1 mg/ml. The ex vivo study showed that the product statistically (p<0.001) decreased melanin pigmentation by 81.53% in the irradiated and treated group when compared to the only irradiated group. Furthermore, the product statistically (p<0.001) increased type 1 procollagen by 260.40%, compared to the only irradiated group. Also, a significant (p<0.05) increase in filaggrin production was observed when compared to the SLS ruptured and untreated group. The clinical study results showed a significant (p<0.001) decrease in skin superficial oiliness after 1 and 4 hours of IP application, compared to the control area (non-treated) and a significant (p<0.001) increase in the dielectric constant after 1, 4, 8, 12, and 24 hours of product application compared to the non-treated area, suggesting an increase in the stratum corneum water content. There was no adverse event, physical sign, or reported sign, showing that the studied cosmetic product presents a high tolerance profile on normal skin. The acne lesion count presented a significant decrease in non-inflammatory lesions (p= 0.0135) and a non-significant reduction in inflammatory lesions (p=0.6641). DRS results analysis showed a significant increase (p<0.05) in the values of I340/I295 (collagen/tryptophan) after a 56 and 84-day period of treatment, suggesting an increase in collagen synthesis on facial skin. The Vectra XT imaging analysis showed that the cosmetic product promoted a significant (p<0.05) reduction in the swelling around the eyes in 95% of subjects after 1 hour of application and after 14 and 28 days of daily use in 100% of subjects (p<0.05). Finally, 120 subjects answered the self-assessment questionnaire, and the product was well appreciated by them: 91% reported their skin was softer, 83% noticed an improvement in the skin's overall appearance, and 93% in skin hydration. The proposed cosmetic product was safe and effective in improving skin conditions and appearance by increasing collagen synthesis, resulting in firmer, less rough, softer, and smoother skin. The reduction of melanin and increase in filaggrin suggest a diminishment in blemishes and more hydrated skin, as shown by Corneometer measurements. In addition, the product was effective for application on oily skin since it reduced the superficial sebum amount and can act in controlling skin hydrolipid balance. In the clinical evaluation, study participants also perceived the improvement in skin hydration and smoothness observed in instrumental measurements. Finally, the present study has an important contribution since it showed the benefits of a cosmetic product based on nanoencapsulated antioxidants using different and innovative evaluation methods.