FORMULATION CHALLENGES

Given the potential cost, compatibility, and skin feel benefits of increased sunscreen efficiency, there have been a number of technologies developed in the past 10-plus years to improve sunscreen products. For example, the use offilm formers, better wetting/spreading emollients, and shear-thinning rheology modifiers allow sunscreen products to spread more evenly and form a uniform film on the skin. A more uniform film leads to increased UV efficacy/efficiency by effectively reducing and/or eliminating “holes” in the product film. The use of combinations of UV filters in both the water and oil phases of emulsions provide increased efficacy/efficiency by ensuring that there are no unprotected areas in the product film. Another example is the identification/development of photostable sunscreen active combinations which allows lower concentrations of UV filters to be used to achieve a UV efficacy target. For systems that are not photostable, much higher concentrations of UV filters are needed to compensate for the loss of UV efficacy that occurs during product exposure to UV on the skin. Finally, the development of newer, more efficient and more photostable UV filters allows formulators to achieve a target UV efficacy with less sunscreen active. Reducing the concentration of UV filters may improve the product aesthetics with the potential for increasing compliance.