Standardized extract of wild apple fruit in alkyl-polyglucoside-based cosmetic cream - estimation of stability, safety, antioxidant activity and efficiency

Int J Cosmet Sci. 2018 May 3. doi: 10.1111/ics.12462. Online ahead of print.

Abstract

Objective: The aim of this study was in vitro and in vivo characterization of cosmetic cream with 6% of wild apple fruit water extract, containing 3.5% of alpha-hydroxyacids-AHAs and polyphenolic compounds, stabilized by biodegradable alkyl-polyglucoside emulsifiers.

Methods: In vitro characterization of cream included organoleptic and physico-chemical (pH values and electrical conductivity) analysis, antioxidant activity-AA estimation (using DPPH test) during 180 days of storage at 22±2°C and determination of cosmetic active substances content-AHAs (using HPLC analysis). In vivo estimation of skin irritation potential after creams application under occlusion during 24h was investigated employing the biophysical methods on 12 healthy volunteers; hydration efficiency, transepidermal water loss-TEWL, skin pH, erythema-EI and melanin index-MI on 10 healthy volunteers after 28 days of cream application and bleaching efficiency on 10 healthy volunteers after 7 days of cream application after artificially induced skin hyperpigmentation.

Results: Investigated cosmetic cream was pale beige color, odorless, semi-solid consistency and homogeneous, with pH values of 6.53±0.14, electrical conductivity above 50 μS/cm and AA of 24.96%RSC after preparation and these characteristics were stable during investigated period. In vivo measurements revealed absence of skin irritation after cream application under occlusion, which was part of it's safety profile. Increase of skin hydration after 14 days of cream application was 17.28±12.23 and after 28 days 21.19±7.59. In addition, in performed experiment TEWL and skin pH values during cream application remained unchanged. Cream application after artificial hyperpigmentation induced decrease of MI (∆MI after 7 days was -45.30±18.55) CONCLUSION: Formulated cosmetic cream with 6% of standardized wild apple fruit water extract and stabilized by biodegradable alkyl-polyglucoside emulsifiers demonstrated good stability, acceptable level of in vitro antioxidant activity, absence of skin irritation after cream application under occlusion and positive effects of cream on human skin after application (hydrating and bleaching effects). All mentioned properties make the cream suitable for possible usage as cosmetic product for preventing the skin damages caused by oxidative stress, for moisturizing the dry skin and bleaching of skin hyperpigmentation. This article is protected by copyright. All rights reserved.

Keywords: alpha-hydroxyacids; cosmetic cream; safety and efficiency; stability; wild apple fruit extract.