Collagen Induction Therapy Without Risk of Hyperpigmentation and Other Topics: Literature Findings

By: Charles Fox, Independent Consultant

Posted: May 29, 2009, from the June 2009 issue of Cosmetics & Toiletries.

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Styrene, unsaturated dicarboxylic acid to soothe skin: L’Oréal discloses a copolymer of styrene and an unsaturated dicarboxylic acid as a nontherapeutic soothing agent for cosmetics, or for pharmaceuticals to prevent and/or treat skin disorders related to skin irritation.³ The invention also indicated the composition for inclusion with cosmetics or pharmaceuticals likely to cause skin irritation. Thus, a cream containing a styrene copolymer 4% was developed.

O/W polyethylene glycol, nonionic surfactant creams: Shiseido Co., Ltd. discloses stable, nongreasy o/w emulsions containing polyethylene glycol and nonionic surfactants for cleansing creams and massage creams.⁴ The disclosed compositions contain: fatty acid soaps; polyethylene glycol with an average molecular weight between 2,000–25,000; nonionic surfactants, one with an HLB between 10–17 and another with an HLB between 2–10; and solid or semisolid oils. An example of a cleansing cream is shown in Formula 1.

Cosmetics to even out skin tone: Kosei Co., Ltd. discloses cosmetics containing block or graft copolymers, partially crosslinked organopolysiloxanes, and powders to even out and correct skin tone.⁵ Specifically, the skin tone- correcting cosmetics contain: block or graft copolymers whose aqueous solutions have a sol-gel transition temperature at > 0°C and < 37°C; partially crosslinked organopolysiloxanes and/or polyether-organopolysiloxanes; and powders having a refractive index of 1.3–1.7. The cosmetics may also contain carbohydrates, water-soluble polymers and/or silicone oils. The example cosmetic shown in Formula 2 exhibited a long-lasting, skin tone-evening effect with good spreadability and moisturization.

Hair and Hair Care
Adenosine-containing cosmetics: Shiseido Co., Ltd. discloses cosmetics containing adenosine that are stable even at low temperatures.⁶ These cosmetics comprise: 1–2% adenosine, 10–20% moisturizers, and 35–65% lower alcohols; they may further comprise cationic polymers and organic acids. An example of a hair tonic is shown in Formula 3.

Nonstaining, even-toned hair dyes: Kosei Co., Ltd. discloses hair-coloring agents containing alkyl acrylate-styrene copolymer, oils and dyes.⁷ The hair-coloring agents spread evenly and easily and provide uniform color to hair without damaging or staining skin or clothes. The disclosed hair-coloring agents contain volatile hydrocarbon oils; an alkyl acrylate-styrene copolymer that is incompatible with the hydrocarbon oils; a solid oil having a melting point of > 80°C; and a pigment and/or dye. An example is shown in Formula 4.