As I write this, I am surrounded by a frozen landscape that lies dormant beneath nearly ten inches of white, drifting snow-fairly conservative for a Chicago winter. I dream of the time when I can peel off my snow boots to dig my bare toes into hot summer sand at the beach.
When summer feels beyond reach, sun care might seem a distant concern; however, the industry has trained me to also envision SPF in my imagined summer-not to mention the fact that winter obviously does not stop UV radiation, or that half of the world is currently in summer. Considering these notions, there is no time like the present to think about sun protection.
The sun care industry faces several challenges, including testing and measuring SPF, questions over the safety of nanotechnology, sunscreen stability, broad-spectrum protection, and inconsistent regulations for allowed UV filters and their combinations. Some of these challenges have plagued product developers for years, thus the industry has had time to develop the means to meet some of them. Recent work in these areas is the primary focus of this issue of C&T magazine.
Having previously quenched the triplet state of UV filters to enable sunscreen stability, Bonda et al. return with a new approach to sunscreen stability: quenching the singlet state, which is shown to quickly and efficiently photostabilize avobenzone, even in the presence of octyl methoxycinnamate.
McCormick et al. explore a micron-sized ZnO dispersion to enable the formulation of transparent yet full-spectrum sunscreen formulations. In addition, Chang and Kwan take a closer look at the free radicals produced from UV-exposed TiO2 to explore how the choice of emulsion may reduce free radical generation. Finally, in related work, Zhai and Maibach describe a rapid and sensitive in vitro method to ascertain antioxidative capacity.
Also, making its debut, “Formulate This” is a new column that will appear regularly to provide cosmetic chemists with practical formulating advice on various topics from seasoned experts. Please send in submissions and feedback to FormulateThis@allured.com. The solutions to sun care challenges featured here are far beyond what I imagined in my barefoot summer vision and my confidence in sun care has never been stronger. It warms my heart (and feet) just thinking about it.