Multiple benefits in sunscreen formulations

Sunscreen sprays and lotions can benefit in a variety of ways when formulated with the polyurethane dispersion Baycusan® C 1000 from Bayer MaterialScience. Although the film-forming polymer itself does not contain any UV-absorbing components, it can boost the sun protection factor (SPF) of a formulation. In addition to having a pleasant skin feel, it also stabilizes emulsions – important particularly for sprays – and lends sun care products very good water resistance.

Formulated with Baycusan® C 1000 that have a very pleasant feel on the skin, meaning that they aren't sticky, waxy or greasy.

New test results confirm the varied benefits of Baycusan® C 1000, which contains neither cosolvents nor preservatives. It has been confirmed, for example, that Baycusan® C 1000 not only shows an SPF-boosting effect in formulations that include the UVB filters octocrylene and ethylhexyl triazone, but significantly increases the SPF of formulations based on broadband UV filters such as bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT) and benzophenone-3. “Baycusan® C 1000 works wonderfully as an SPF booster, particularly for formulations containing the modern, high-performance filter BEMT,” says Dr. Sophie Viala, global head of Business Development for Cosmetic Raw Materials at Bayer MaterialScience. “More cost efficient products can be formulated with Baycusan® C 1000 that have a very pleasant feel on the skin, meaning that they aren't sticky, waxy or greasy.”

Baycusan® C 1000 also acts as a stabilizing raw material for oil-in-water (O/W) emulsions.. Scientists at Bayer MaterialScience took advantage of this property to develop a sunscreen spray with a very low concentration of emulsifier. This low-viscosity formulation exhibits high water resistance, as confirmed by in vivo tests conducted in accordance with guidelines established by Colipa, the European Cosmetics Association. “With Baycusan® C 1000, our customers are well-equipped to master the challenge of formulating sunscreen sprays with both high water resistance and high SPF,” says Dr. Viala.

There are also new results regarding the film-forming properties of Baycusan® C 1000. A film of the polyurethane dispersion on artificial skin film withstood mechanical stress with virtually no visible damage, unlike the acrylate copolymer film, it was compared to. Films based on Baycusan® C 1000 are very flexible, move with the skin and allow it to breathe, making sunscreens formulated with this dispersion very comfortable to wear.

Bayer MaterialScience will be presenting Baycusan® C 1000 and our other cosmetic products at In-Cosmetics 2011, from March 29 to 31, 2011, in Milan, Italy.