Impact of Polymers on Texture Properties of Cosmetic Emulsions: A Methodological Approach
Résumé
A methodology, particularly well adapted to the evaluation of cosmetic creams containing various texturing agents, is defined here using the Spectrum Descriptive Analysis method. The objectives were to describe and to understand the contributions of the texturing agents to the texture attributes of oil‐in‐water emulsions. The study focused on eight hydrophilic polymers, either natural (e.g., xanthan), semi‐synthetic (e.g., hydroxypropyl guar) or synthetic (e.g., carbomer), incorporated each one in an o/w emulsion. Eight texture attributes were selected and precisely defined, with strict evaluation procedures and notation scales. These attributes were gloss, integrity of shape, penetration and compression forces, stringiness, difficulty of spreading, absorbency and stickiness. A quantitative frame of reference was also developed. The methodology accuracy was evaluated through statistical analysis thus proving the sensory panel was highly discriminative, reproducible and repetitive. Principal component analysis underlined that polymers conferred to creams a very different skin feel when compared to the “control” emulsion without polymer. Synthetic polymers were characterized by higher consistency and lower gloss; semi‐synthetic polymers and xanthan by higher degrees of stringiness, whereas carob exhibited intermediate properties.