Orange Roughy Oil for Sensitive Skin and Other Topics: Literature Findings

By: Charles Fox, Independent Consultant

Posted: March 31, 2009, from the April 2009 issue of Cosmetics & Toiletries.

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Thus, molecular targets for skin pigmentation associated with aging should be focused on mechanisms related to the EMU. There are three basic approaches. The first is the melanin/melanosome exfoliation process, which can be subdivided into exfoliation of horny-layered cells, accelerated growth of these cells, and their water and sebum content. The second is the transfer and degradation of melanin/melanosomes, which concerns molecules affecting the growth and differentiation of either melanocytes, keratinocytes or both. The third target are the molecules responsible for melanin and melanosome biosynthesis.

The step-by-step dissection of each of these processes should provide improved or novel management of aging-related facultative skin pigmentation.

Sunscreens
Photostable UV absorber: Shiseido Company Ltd. has disclosed sunscreens including dibenzoylmethane derivatives in combination with alkyl diphenylacrylate and benzalmalonate derivatives¹⁰ that do not hinder the photostabilizing effect of the dibenzoylmethane derivatives. The composition is an effective UV absorber across a wide wavelength range, from UVA to UVB. Specifically, the composition contains a dibenzoylmethane derivative; an alkyl beta, beta-diphenylacrylate and/or an alpha-cyano-beta, beta-diphenylacrylate (for example, octocrylene); and a specific benzalmalonate derivative; for example, di-(2-ethylhexyl)-4-methoxybenzalmalonate.

Broad-spectrum UV filter: Herzog et al. review the development of broad-spectrum UV filters for cosmetic applications.¹¹ Modern sunscreens must protect against both UVB and UVA radiation. This requires UVB absorbers as well as photostable UVA or broad-spectrum UV filters. Bis-ethylhexyloxyphenol methoxyphenyltriazine (BEMT)a is a hydroxy-phenyl-triazine derivative that is designed for optimal spectral performance and solubility in cosmetic oils. Due to its molecular structure, the material exhibits a UV spectrum with two absorption peaks, indicating broad-spectrum protection even at the low concentration of 2%. It also exhibits efficacious photostability based on rapid photo-tautomerization, recognized by a change in molecular configuration brought about with exposure to UV.

The material can efficiently stabilize photo-labile UV filters such as T-butylmethoxydibenzoylmethane or ethylhexyl methoxycinnamate. Furthermore, it shows a synergistic effect on SPF with commonly used UVB filters as well as with bis-benzotriazolyl tetramethylbutylphenol.^b