Study shows W/O microemulsion effectiveness for oily make-up removal
Due to the increase in oily cosmetics use, the requirement for cleaning products for efficient removal of these products is also increasing.
However, because silicone resins or hydrophobic polymers that are used to enhance the sustainability of make-up are highly waterproof, water-soluble surfactants that operate by adsorption are inefficient for removal of oily make-up.
Therefore, the development of cleaning products that are effective in removing oily cosmetics without irritating facial skin is required, and this is what led the research group from the Department of Fine Chemistry, Cosmetic R&D Center, Seoul National University of Science and Technology, to this study.
Research
They prepared W/O microemulsions with seven oils and three emulsifying systems to assess their cleaning characteristics, which was compared by evaluating the wettability and emulsifying activity.
The wettability and emulsifying activity were, respectively, evaluated by measuring contact angle and absorbance after preparing a total of 20 samples using three emulsifying systems and seven oils.
They found that the wettability of the microemulsions, evaluated based on the contact angle, increased as the inorganic organic balance value of the oil component increased at certain parameters, as did the emulsifying activity.
This in turn saw the cleansing power increase at certain parameters and the scientists were then able to determine the most efficient parameters for removal of oily make-up cosmetics.
Results
Based on the results, a lower viscosity of the oil component is favourable for higher wettability, and the lower the viscosity of the emulsifying systems, the higher the wettability of the microemulsion.
Except in the case of oleic acid (OA), oils having high polarity showed significant emulsifying activity. The equation describing inline image was derived from the detergency measurement results, and it was verified.
“It is concluded that the impact of the wettability is more significant than the emulsifying activity for determining the detergency of the microemulsion, because standardized regression coefficient of wettability and EAI derived from Eq. (3) was, respectively, 0.99 and 0.22,” say the study authors in the Journal of Cosmetics Science.
“It is anticipated that the evaluation of the physicochemical characteristics of the W/O microemulsions prepared in this study should contribute significantly to product development for efficient removal of oily make-up cosmetics.”
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Kim, E. J., Kong, B. J., Kwon, S. S., Jang, H. N. and Park, S. N. (2014), Preparation and characterization of W/O microemulsion for removal of oily make-up cosmetics. International Journal of Cosmetic Science, 36: 606–612. doi: 10.1111/ics.12163
