Studies were carried out by the FDA that showed nanomaterials, such as zinc oxide and titanium dioxide ( ZnO and TiO2), to be safe, with indications from the industry that these ingredients go a long way to protect against skin cancer.
This was supported further by the Personal Care Products Council, with Farah Ahmed, chair of the sunscreen task force saying the following:
“We are also pleased that FDA reaffirmed there are no safety issues with any of the sunscreen active ingredients, including nanoscale titanium dioxide and zinc oxide.”
“The agency confirmed that it evaluated available scientific literature, tested sunscreen nanoscale ingredients and concluded they do not penetrate the skin,” he added.
Surge in sun formulation
And ingredients supplier Croda told CosmeticsDesign.com that it is optimistic that the recent FDA announcement will prompt a surge in sun formulation innovation in the US.
Croda says that many of its customers understandably felt unable to invest much time in formulating sunscreens while the future rules were not known.
“The clarity provided recently regarding efficacy and testing will release customers to refresh their UV protection offerings and take advantage of recent advances in sun care ingredients” said Jennifer Hart, sales and marketing director for Sun care and Biotechnology.
Nanopigments such as titanium dioxide and zinc oxide are minerals already present in our natural environment, according to the European Cosmetics Association, Colipa.
They are used in sunscreens for their capacity to reflect and scatter UV light thus protecting human skin against adverse effects of UV radiation, including skin cancer. In sunscreen lotions, nano TiO2 is present in large clusters whose size is much greater than 100nm to ensure optimal protection of the skin.
UV filters: organic vs inorganic
Sun products may contain several different UV filters to provide a broad spectrum of protection. Individual filters tend to be effective at different wavelengths of ultraviolet light.
Broadly speaking, there are two types of UV filter: organic and inorganic (mineral) filters.
The organic filters absorb the ultraviolet light and convert it into a small amount of heat. Organic filters are the most commonly used UV filters but they are often supplemented in products with inorganic filters to increase the efficacy.
Inorganic filters can reflect, scatter and absorb the UV light depending on the size of the particles. The absorption and also efficacy is increased when the size is smaller. When particle size is not sufficiently small there is a skin whitening effect and the products are less cosmetically acceptable. Inorganic filters protect against both UVA and UVB radiation.
For example, nanopigments such as titanium dioxide and zinc oxide are minerals that are used in some sunscreens as filters where they ensure protection of the skin. Moreover, their transparency facilitates usage and therefore acceptance by consumers.
Nowadays there is a vast array of inorganic-enabled possibilities available for formulators and developments have shown advantages can be taken in using a combination of organic and inorganic sunscreens to achieve high SPF products with good photostability, while retaining enough formulation flexibility to allow attractive sensorial properties for the consumer.
With a selection of options available from leading ingredient suppliers, the FDA announcement and backing of the use of inorganic filters allows formulators to fully embrace them going forward.