Film former from Bayer MaterialScience proves effective in water resistant sunscreens

Water-resistant and cost-optimized formulations with very high sun protection factors and sensory advantages are the leading trend in modern sunscreen products. Bayer MaterialScience is introducing these trends to the global professional public at In-Cosmetics in Paris from April 16 to 18, 2013. The company's cosmetics team is presenting formulations based on the film-forming dispersion Baycusan® C 1000.

The dispersion is extremely well suited to modern oil-in-water sunscreen formulations because it acts as a stabilizer in such systems. The film-forming agent can be used with or without emulsifiers. This prevents re-emulsification under the influence of water, and the products largely retain their protective effect. What is more, they display high water resistance, a critical requirement for modern sunscreen formulations.

"Using Baycusan® C 1000 is particularly advantageous in spray emulsion systems, because it essentially does not raise the viscosity," says Martin Krause, regional technical manager for Europe and Latin America on the cosmetics team at Bayer MaterialScience.

This year Bayer is focusing on formulations with a high sun protection factor (SPF), i.e. SPF 50 and higher. In these sunscreen formulations, the film-forming dispersion Baycusan® C 1000 forms a flexible, non-occlusive film. It moves in accord with the skin and enables a naturally soft, non-sticky skin feel. Such sensory advantages, combined with high sun protection factors, are very difficult to achieve.

Another advantage is the SPF-boosting effect confirmed in in vivo studies by a neutral testing institute. The polyurethane dispersion can significantly increase the SPF in formulations containing Octocrylene, Ethylhexyl Triazone (both UV-B filters), bis-Ethylhexyloxyphenol Methoxyphenyl triazine (BEMT) or Benzophenone-3 (broad band UV filters), although the dispersion itself does not contain any UV-absorbing groups. "This means that by using Baycusan®, our customers can reduce selected UV filters and offer cost-optimized formulations," says Dr. Paula Rodrigues, global head of Cosmetic Raw Materials at Bayer MaterialScience. "Another synergistic side-effect of reducing some UV filters is the improved skin feel that results," adds Dr. Sophie Viala, who is responsible for the worldwide technical development of cosmetic raw materials.

Additional findings relate to the incorporation of Baycusan® C 1000 in formulations. The preservative-free film-forming agent can be incorporated into common formulations without neutralization and without a high energy input, most effectively by using a hot/cold method in an industrial manufacturing process.

Source: Bayer MaterialScience