Diethanolamine Esterquats for Hair and Skin and Other Topics: Literature Findings

By: Charles Fox, Independent Consultant

Posted: May 4, 2009, from the May 2009 issue of Cosmetics & Toiletries.

This month’s survey of recent patent and research literature describes moneymaking ideas for personal care product development including water-induced thickening of hair, surfactant/biopolymer mixures, a foam/aerosol hair conditioner, and yeast glucan carriers, among others.

Skin and Skin Care
Magnesium ascorbyl phosphate in skin lightening: Nakama et al. indicate that magnesium ascorbyl phosphate (MAP) inhibits the transfer of melanin granules from melanocytes to keratinocytes.¹ In skin lightening, this transfer is important to control and many studies have been conducted regarding the transfer mechanism of melanin granules; however, few studies have examined the mechanism of intercellular adhesion between melanocytes and keratinocytes. These researchers investigated the role of epithelial cadherin (E-cadherin), a cell adhesion factor, on the UV-induced acceleration of melanin transfer, revealing that nitric oxide, a skin melanogen induced by UV irradiation, accelerates the transfer of melanin granules from melanocytes to keratinocytes. Furthermore, nitric oxide was found to up-regulate the expression of E-cadherin mRNA in human melanocytes and keratinocytes.

On the other hand, MAP, a vitamin C derivative, inhibited nitric oxide-induced acceleration of melanin transfer and the up-regulation of E-cadherin mRNA expression. These results suggest that E-cadherin regulates the transfer of melanin granules, and that MAP inhibits the acceleration of melanin transfer by regulating the expression level of E-cadherin. On the basis of these results, MAP was found top be an effective, multifunctional ingredient with application in skin lightening products. In such products, it has been shown to reduce and inhibit melanin formation and melanocyte proliferation.

In-shower body lotion for dry skin: Ertel et al. have published a controlled exposure method to predict the benefit of an in-shower body lotion for dry skin.² Since in-shower body lotions are designed to be used in the shower after cleansing and followed by rinsing, existing predictive methods for cleansers or leave-on lotions are not applicable. Protocol parameters were chosen on the basis of consumer habits, practice studies and randomized clinical testing. The resulting protocol is reportedly consumer-relevant and reliably and reproducibly predicts dry skin improvement from in-shower body lotion product forms.

Skin perturbation with surfactant/humectant systems: Ghosh et al. have published on the visualization and quantification of skin barrier perturbation induced by surfactant/humectant systems using two-photon fluorescence microscopy.³ To visualize the effects of aqueous surfactant/humectant systems on the skin barrier, an in vitro two-photon fluorescence microscopy (TPM) study including dual-channel visualization was conducted. TPM is a noninvasive imaging technique with the capability for imaging up to several hundred micrometers deep that is based on photon-induced nonlinear excitations of fluorophores.