Copyright © Françoise Herrmann
The US manufactured, Australian Blue Lizard® sunscreen with a patented Smart Bottle™
that turns blue in the presence of UV radiation, also uses a patented zinc oxide Z-cote® formula. According to the inventors, Zinc oxide is the most effective, stable and safe, broad spectrum UVA and UVB protection agent. The Z-cote® formulation of zinc oxide, disclosed in the WIPO patent application WO2013173336, titled Easily formulated Zinc oxide, is a patented process that micronizes zinc oxide into nanoparticles with a mean particle distribution (D50) ranging between 300 nm to 600 nm (with no particles smaller <100 nm), and further coats the particles to make them hydrophobic (resistant to water). This coated nanoparticle zinc oxide powder has the advantage of dispersing evenly (without clustering) in the rest of the formula, and on the skin, thus providing users with an even zinc oxide application, which both protects from harmful UVA and UVB radiation, and remains resistant to water.
Thus the patented Z-cote® process means that you can retain sun protection in the water, and use the sunscreen for sports activity, where sweating will not make the formula run into your eyes or off your skin. Indeed, Blue Lizard® claims that their Sports formula and Very water resistant Regular formula afford 240 minutes of protection is whirlpool water, which amounts to three times more than the US standards for water resistant sunscreen (set to 80 minutes).
Cool sunscreen… for runners, triathletes, bikers, tennis players… plus more… outdoor folks, now that summer is around the corner!
The abstract of patent application WO2013173336, titled Easily formulated Zinc oxide, appears below with an image above of the marketed Sports and Very water resistant Regular formulas for Blue Lizard® Sunscreen.
The present disclosure relates to polymeric siloxane coated zinc oxide powders having a mean particle size number distribution (D50) ranging from about 300 nm to about 600 nm and their use in sunscreen compositions. The relatively high surface area (in relation to particles of <100 nm) avoids agglomeration resulting in ease of formulation and high dispersal of the particles which tends toward less light scatter and hence better transparency in formulations. Furthemore, the combination of the particular particle size number distribution (D50) of zinc oxide ranging as above with bis(resorcinyl)triazine UV absorbers shows unexpected increased UV-A absorbance (320 to 400 nm) in comparison to the zinc oxide and bis resorcinyl triazine UV absorbers on their own at the same concentration.