18684 A scoring method to assess the gentleness of cleansers

Abstract

Surfactants are a key component of skin cleansers to remove unwanted substances. Paradoxically, surfactants also interact with proteins and solubilize lipids in the stratum corneum, which weakens the skin barrier and results in loss of moisture, oxidative stress and inflammation. This leads to physiological changes that can exacerbate sensitive skin conditions. Our aim is to create a scoring system to help consumers and professionals differentiate the gentleness of cleansing products. The result is a 5-star rating for gentleness, whereby a high rating of 5 out of 5 stars suggest that the cleanser is gentle on normal skin. The gentleness scoring system is based on both formulation characteristics, and in vitro assessment. The formulation will be evaluated for the presence of mildness enhancers, absence of allergens and sensitizers, and pH of formulation that falls within skin pH range. These three attributes of formulation characteristics are of equal weightage and contribute to 2.5 out of 5 stars. The remaining 2.5 stars are determined by the gentleness of the surfactant system via in vitro methodologies. The impact of the surfactant system on the skin barrier will be visualized by multiphoton microscopy to assess surfactant penetration through the epidermis. Loss of stratum corneum lipids will be quantified by Fourier-transform infrared spectroscopy. The in vitro results will be analyzed as a fold difference relative to negative control. Thus, a gentle formula with minimal impact to the skin barrier will obtain a higher gentleness score that will be validated by either a clinical or consumer study.