Spreading behavior of cosmetic emulsions: Impact of the oil phase. (December 2018)

• Record Type: Journal Article
• Authors: Gore, Ecaterina; Picard, Céline; Savary, Géraldine
• Is Part Of: Biotribology. Volume 16(2018)
• Page Start: 17
• Page End: 24
• Publication Date: 2018-12
• Subjects: Spreading -- Emollient -- Skin -- Oil phase -- Emulsion; Biological interfaces -- Periodicals; Biomedical materials -- Periodicals; Biomechanics -- Periodicals; Tribology -- Periodicals; 610.2805
• DOI: 10.1016/j.biotri.2018.09.003
• Languages: English
• ISSNs: 2352-5738

Abstract

Abstract: Background: Emollients are an important ingredient in personal care products, they are currently prescribed in skin disorders like eczema, which affects up to 30% of children in developed countries. Methods: The aim of the study was to investigate the impact of two emollients (stearic acid and isohexadecane) and their mixtures in the spreadability and frictional effect on films obtained from oil-in-water emulsions. Rheological, textural, sensory and tribological analysis were performed on human skin and artificial substrates. Results: The emollients ratio influences the spreading behavior of emulsions: more isohexadecane in the oil phase easier to spread the product on the skin. Moreover, significant correlations were obtained for the spreading behavior obtained by textural measurements on artificial substrates and sensory analysis (Pearson coefficient = −0.871). The results obtained by frictiometer showed different developments over time after product application: the friction values increase with the stearic acid concentration in emulsion. Discussion: This study showed the importance to consider the emollient properties when one emollient is used in the emulsion, but especially their interactions, when several emollients are used, to better understand and anticipate their behavior. First, spreading was governed by the consistency of the emulsion, particularly impacted by the emollients ratio. But then, in a long-time spreading, when the emulsion broke down and residual film was formed, a particular interaction with skin influenced the spreadability. It appears that not only the physical state of the emollient but also its chemical nature, physical state, polarity, temperature might explain these phenomena. Graphical Abstract: Highlights: Consistency of emulsions directly governs the sensory perception of spreading The nature of the emollients and their ratio affect the spreadability More liquid emollient in the oil phase, easier to spread the emulsion on skin The type of emollient affects long-term spreading inducing skin-emulsion interactions