Natural Hair Dyes, Self-tanning Solutions and Other Topics: Literature Findings

By: Charles Fox, Independent Consultant

Posted: October 30, 2009, from the November 2009 issue of Cosmetics & Toiletries.

Skin and Skin Care
Pyrus pyrifolia wrinkle reduction: Ansung Machum Association introduced an antiwrinkle and antiaging cosmetic composition containing 0.05–5.0% w/w Pyrus pyrifolia extract.¹ The composition is said to exhibit: an antioxidant effect due to DPPH-eliminating activity; hydroxyl-eliminating, superoxide anion-eliminating and singlet-oxygen-eliminating activity; and a skin-lightening effect due to tyrosinase and melanin synthesis inhibition. In addition, the composition imparts an antiwrinkle effect due to elastase and collagenase inhibition, and an anti-inflammation effect due to lipoxygenase inhibition. The composition is said to inhibit skin aging and reduce the appearance of wrinkles. Also, it has low toxicity.

Urokinase inhibitors for barrier repair: Pentapharm AG published research on 4-amidinobenzylamine urokinase inhibitors for barrier repair in cosmetic and/or dermatological applications.² In addition, compositions and non-therapeutic methods for the cosmetic treatment of skin and the scalp are disclosed. Urokinase inhibitors can be used to prevent damage to and restore the epidermal barrier. Barrier abnormalities and disruptions are often the starting point of a dry skin state and include itching, dandruff and the perception of sensitive skin. The described 4-amidinobenzylamine derivatives can be used in topical skin and scalp care creams, lotions, gels and shampoos to protect against these conditions.

An emulsion was prepared from four phases, the last of which contained benzylsulfonyl-D-der-gly-(4-aminobenzylamide). The correlation of transepithelial water loss and plasmin to urokinase activity in the stratum corneum (SC) was tested, showing that urokinase and plasmin are inhibited by the amidinobenzylamines on the top layers of the SC.

Carboxylic acids to clean aged skin: Henkel AG & Co. disclose hair and skin cleansers with low pH-containing hydroxycarboxylic acids and ketocarboxylic acids for application to aging skin.³ The cleansers contain water; a mild surfactant system with a maximum of 0.5–20% w/w surfactant; and at least 2% w/w alpha-hydroxycarboxylic acid, beta-hydroxycarboxylic acid and/or ketocarboxylic acid. The pH of the composition is 3.5–4.5. An example of an antiwrinkle cleansing gel is shown in Formula 1.

Fatty acid combos for shower moisturization: Unilever PLC discloses in-shower lotion compositions comprised of up to 10% w/w free fatty acids with the ratio of unsaturated to saturated fatty acids of at least 1:1.⁴ These rinse-off, skin-conditioning compositions comprise relatively low amounts of oil/emollient and aqueous phase stabilizer/structurant. Unexpectedly high hydration was found with the incorporation of an unsaturated fatty acid, such as oleic acid, as a percentage of the total fatty acid. In a second embodiment, superior hydration resulted from the use of a branched fatty acid, such as isostearic acid, with a minimum amount branched as a percentage of the total fatty acid. Mixtures of unsaturated and branched fatty acids also can be used.