Boosting SPF with Copolymers and Other Topics: Literature Findings

By: Charles Fox, Independent Consultant

Posted: April 30, 2010, from the May 2010 issue of Cosmetics & Toiletries.

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where AO = C3-4 oxyalkylene; EO = oxyethylene; m = 1-70; l + n = 1-70; R1, R2 = C1-4 hydrocarbyl, H; and the ratio of EO to all oxyalkylene units is 20–80% w/w. An example, shown in Formula 5, exhibited low irritation to the skin, good spreadability and hair damage-repairing properties.

Reducing perm damage: Mandom Corp. has patented permanent wave-setting kits that suppress damage and condition hair.9 The first agent applied from the kit contains a reductant. The second agent applied contains an oxidant, monoalkyl quaternary ammonium-type cationic surfactants, amino-modified silicones, lanolin fatty acid aminopropylethyldimethylammonium ethyl sulfate and polyether-modified silicone surfactants. A permanent wave solution for bleached hair, shown in Formula 6, resulted in good gloss, smooth feel and excellent combing properties.

Makeup
Swelling effect for lip care: Coty Deutschland GmbH has disclosed two-part lip compositions that are combined and applied to the lips for a swelling effect.¹⁰ The first composition comprises: a siloxane polymer with at least two hydroxy-functionalized terminal groups or hydroxy-functionalized side chains, and/or a polyol with at least two hydroxyl groups; and either a catalyst or a hydrosiloxane with at least two Si-H units; the second composition contains either the catalyst or hydrosiloxane—whichever is not present in the first composition.

When the two parts of the composition are combined, the catalyst catalyzes in situ cross-linking of the siloxane polymer or polyol and the hydrosiloxane with dehydrogenative coupling to form a foamed elastomeric transfer-resistant film. The formula for a two-part lipstick composition is shown in Formula 7.

Sunscreens
Spray congealing for avobenzone: Albertini et al. have evaluated spray congealing as a technique for the preparation of highly loaded, solid lipid microparticles (SLMs) containing the sunscreen agent butyl methoxydibenzoylmethane (avobenzone) to potentially reduce its photoinstability.¹¹ The microparticles were produced using the lipidic material carnauba wax and the surfactant phosphatidylcholine via either the classical melt dispersion method or spray congealing through a pneumatic atomizer.