Abstract

Consumer wishes change based on a growing consciousness for the environment and people. Also, regulations change and evolve due to current and updated scientific findings. This also affects the range of commonly used UV filters. As an industry, we develop products that address these trends and meet those requirements. Consequently, we must find innovative ways to develop and optimize sunscreen products where SPF boosters play an important role. 

SPF boosters shall increase the value of SPF and preferably UVA-PF and allow to reach higher sun protection factors with the same amount of UV filters. These products are not considered as UV filters because they, alone, do not significantly contribute to SPF or UVA. But they can help sunscreen formulators to answer the demands for high SPF products while considering a limited choice of UV filters. 

In the pursuit of developing a SPF booster based on renewable and biodegradable raw materials we have evaluated potential candidates for their efficacy. These were incorporated in sunscreen preparations and compared to a placebo formulation without SPF booster, starting with in-vitro measurements of the UV absorbance based on ISO 24443:2021, followed by evaluation of the impact of the SPF booster concentration. The most promising candidates were further tested on their performance in water-in-oil as well as oil-in-water emulsion systems and with mineral and organic UV filters according to the different in-vivo methods ISO 24444:2019, FDA monograph standard 21CFR201.327 and hybrid diffuse reflectance spectroscopy.

To extend the set of data the influence of UVA and UVB absorbance was examined as well as the impact on the sensorial profile when adding a SPF booster to an already existing formulation.

Showing outstanding efficacy in in-vitro and in-vivo evaluations of the sunscreen protective properties the wax blend SymEffect™ UV performs in different emulsion systems and works with a variety of UV filter combinations to boost the SPF. Additionally, the balance between UVA and UVB absorbance of the initial sunscreen formulations is kept on the same level when including the wax blend, and the final sensory profile is comparable to the placebo formulations.

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