Quantification of Lipid Phase Order of In Vivo Human Skin Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy and Multivariate Curve Resolution Analysis.

A new analysis methodology utilizing multivariate curve resolution (MCR) has been successfully combined with Fourier transform infrared (FT-IR) measurement of in vivo human skin to resolve lipid phase constituents in the spectra relative to high and low chain ordering. A clinical study was performed to measure lipid order through different depths of stratum corneum of human subjects. Fourier transform IR spectra were collected through the top 10 layers of the skin on four sites on the left and right forearm of 12 individuals.

Effects of anionic surfactants on the water permeability of a model stratum corneum lipid membrane.

The stratum corneum (SC) is the ourtermost layer of the epidermis and has a brick-and-mortar-like structure, in which multilamellar lipid bilayers surround flattened dead cells known as corneocytes. The SC lipid membranes provide the main pathway for the transport of water and other substances through the SC. While the physicochemical properties of the SC can be affected by exogenous materials such as surfactants, little is known about how the water barrier function of the SC lipid membranes is compromised by common surfactants.