Water-soluble UV Filters and Other Topics

By: Charles Fox, Independent Consultant

Posted: January 30, 2009, from the February 2009 issue of Cosmetics & Toiletries.

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The first step is applying a reducing composition on the keratinous fibers to reduce the keratin disulfide bonds. Waving of the keratinous fibers can occur before, during or after this application.

The second step is fixing by oxidation and reshaping those bonds by applying an oxidizing composition containing at least an oxidizing agent and at least a cationic polymer thickener. The thickener is the product of the polymerization of a mixture of monomers. The monomer mixture includes at least one of each of the following: a nonionic hydrophobic vinyl monomer, a surfactant vinyl semi-hydrophobic monomer, and a vinyl monomer substituted by at least an amine group.

In one example from the patent, a reducing composition was applied on the hair in an iron curler for 15 min. Then the hair was washed and the oxidant composition shown in Formula 4 was applied to obtain a permanent hair wave.

Hair removal: Reckitt Benckiser (UK) Ltd. discloses epilatory compositions comprised of a rosin-based or sugar-based material and, mixed with the matrix material, particulate silica, and a polymer or copolymer.¹⁴ Preferably the silica is fumed and colloidal; and the polymer is polyethylene or block copolymers of hydrocarbon-polyether-polyamide or polyether-hydrocarbon types. The particles reduce the tendency of the epilatory composition to flow, under warm ambient conditions. Also disclosed is an epilatory product and a method of epilation.

An example is shown in Formula 5. Hair removal percentage for the composition was at least 10% higher than with no polymer/copolymer.