Activities of hydroxyproline: Kobayashi et al. review the manufacture and physiological activities of hydroxyproline. The authors state that hydroxyproline is a safe and useful cosmetic material. Additional topics discussed include the following: the manufacture of hydroxyproline by microbial fermentation and the increase of ceramide synthesis by hydroxyproline through activating proliferation of epidermal keratinocytes; promotion of the collagen production in dermal fibroblast and epidermal keratinocytes; wrinkle-repairing effect; and effect on photoaged skin and atopic dermatitis.
Increasing selectivity in skin cleansing: Beiersdorf describes the use of surfactants with a ratio of hemolysis value to denaturation index of greater than or equal to 1 for increasing the selectivity of skin cleansing preparations. Selective cleansing activity is related to the removal of surface and sebum lipids rather than barrier lipids. An example of such a cleansing preparation is shown in Formula 1.
Polyethylene glycols in skin and hair care: Clariant describes hair and skin preparations containing polyethylene glycols (PEG) with a preferred polymerization degree of 300-800. PEG improves wet hair combability. Further, the preparations contain the cationic guar hydroxypropyl-trimethyl ammonium chloride. Shampoos, shower soaps and hair conditioners are described.
