Preparation and characterization of W/O microemulsion for removal of oily make-up cosmetics

Synopsis Objective: In the present study, W/O microemulsions (MEs) were prepared for efficient removal of oily make-up cosmetics and the detergency characteristics were studied. Methods: The W/O MEs were prepared by mixing of a spontaneous emulsifier, cosurfactant and oil, and solubilizing the mixture during addition of water. 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. 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 ME. Except in the case of oleic acid (OA), oils having high polarity showed significant emulsifying activity. The equation describing [detergency (Delta E) = 98.1 wettability (cos theta) + 120.05 EAI (emulsifying activity index) - 77.1] was derived from the detergency measurement results, and it was verified that the wettability contributed more significantly to the detergency than the emulsifying activity. Conclusion: These results suggest that the prepared W/O microemulsions can be utilized as cleaning agents for efficient removal of oily make-up cosmetics.