Stability, antioxidant activity, in vivo safety and efficacy of creams with standardized wild apple fruit extract: a comparison of conventional and biodegradable emulsifiers

Objective The aim of the study was in vitro and in vivo characterization of cosmetic cream with 6% of standardized wild apple fruit extract, stabilized by conventional non-ionic emulsifier-CEW, in order to determine the influence of emulsifiers (conventional vs. biodegradable) on the characteristics of creams and their effects on the skin. Methods Organoleptic and physico-chemical (pH values and electrical conductivity) analysis was performed, determination of fruit acids-FAs content (using HPLC analysis) and estimation of its antioxidant activity-AA (using DPPH test) during 180 days. In vivo study included following examinations: screening of safety profile (after creams application under occlusion during 24 h at human skin); skin moisturizing potential, transepidermal water loss-TEWL, skin pH after 28 days of cream application and hypopigmentation efficacy 7 days of cream application at artificially induced skin hyperpigmentation. Results Investigated cosmetic cream-CEW showed satisfactory organoleptic, physico-chemical characteristics, stability, FAs content (0.13%) and AA (19.25 +/- 0.67 %RSC) after preparation, which remained unchanged over the study period. In vivo investigation revealed absence of skin irritation after CEW's application under occlusion. An increase of skin moisturization (after 14 days Delta EC was 18.52 +/- 11.51 and after 28 days of applications 16.52 +/- 9.36) during 28 day-study, with unchanged TEWL and skin pH values was shown. Decrease of melanin index was revealed, too (after 7 days Delta MI was -31.40 +/- 16.50). Conclusion Cosmetic cream stabilized by conventional emulsifier showed better antioxidant potential and weaker moisturizing and hypopigmentation effects related to the cream with same composition but stabilized by biodegradable emulsifiers. Based on all mentioned above, investigated cosmetic cream might be considered for potential use as modern, stable, safe and efficient cosmetic product in the prevention and/or treatment of oxidative stress-related skin changes and/or damages, for moisturization of dry, even irritated skin as well as for lightening of hyperpigmented skin.