TAGS: Decorative Cosmetic
Kao researchers of Analytical Science Laboratory and Makeup Research Laboratory have developed a new evaluation method that visualizes composition and distribution of each component inside the film formed by base makeup such as foundation by use of Raman spectroscopy without disruption of the film. With use of this technique, composition distribution inside base makeup film as well as sebum characteristics can be revealed.
Composition of Base Makeup Film
Initially, base makeup film samples were prepared using a commonly used liquid foundation, then observed by Raman spectroscopy. However, the internal structure could not be analyzed because of destruction of the film by laser-generated heat. In addition, the Raman signals for some of the components were excessively strong, making precise visualization impossible.
Further examinations showed that iron oxide and titanium dioxide interfered with specific analysis of the base makeup. Therefore, a model formulation was prepared by replacing those with talc, which allowed for successful visualization of the composition of the base makeup film, including organic and inorganic substances, as well as distribution of each component in cross-sectional images.
The results confirmed that powder, lipophilic, and hydrophilic components formed micrometer-sized aggregations inside the base makeup film. In addition, the film was shown to be constructed by complex interactions of these components.
Sebum Distribution in Base Makeup Film
The behavior of sebum, a major cause of makeup deterioration, was examined as a test application of this novel technique. It was anticipated that sebum distribution in the film would be visualized by adding sebum to the base makeup film prepared with a model formulation.
However, the oil contained in the base makeup, including silicon and UV absorber, as well as in the sebum model could not be discriminated, thus a highly sensitive detection technique that replaced some atomic elements of the sebum model with deuterium was adopted.
Using this technique, evaluation of the base makeup film was possible in terms of sebum resistance. It was confirmed that sebum was not spread throughout the film, but rather was localized between the base makeup components. The present findings suggest that base makeup film with sebum resistance can contribute to prevention of makeup deterioration due to sebum.
The novel technique clarified composition distribution and sebum behavior in base makeup film, which were previously difficult to understand or clearly observe. Kao will make use of this new evaluation method for future development of base makeup products with greater functionality.
Source: Kao