A Study of the Optical Properties of Cosmetics Measured by Polarized Light Goniophotometry

Abstract

Polymethylmethacrylate powders are commonly used to improve the spreadability and blurring effects of powder foundation cosmetics. In this study, the opacity and haze effect of four types of polymethylmethacrylate powders and their 10wt% powder foundation formulation was evaluated. The distorted random hemispherical particulates with both concave and convex portions showed the highest haze and opacity value as a single powder substance. And as a formulated phase, the powder foundation formulation containing particulates with fine pores provided the highest haze and opacity value. We also examined the quantity of reflected light over the angular range 20-75° by polarized light goniophotometry. The total reflected light intensity, surface-reflected light, and internally reflected light were characterized. These studies demonstrated that hemispherical PMMA powders produce natural brilliance by creating high internally reflected light which is similar to the total reflection profile of artificial skin.

Deep skin homogeneity and light diffusion: An accelerated Monte Carlo model for in vivo skin characterization and consumer perception

“…The collagen matrix in the upper dermis of human skin is known to act as a strong light scatterer. Its degradation with age decreases scattering and thereby the reflectance of visible light [26–29]. The lateral diffusion lengths of light do not show any correlation at any wavelength with age.…”

“…Diffuse light reflectance spectroscopy (DLRS) has been widely used to characterize skin components and changes with treatments [26,[29][30][31][32][33][34]. The present approach focuses on the internal skin propagation of light, which is usually masked by a broad light source commonly used in DLRS and general skin imaging techniques.…”