Interview with Sven Klare, Technical Manager Applied Innovation Sensory Additives, Cosmetic Solutions, Evonik

Sven Klare
Technical Manager Applied Innovation Sensory Additives, Cosmetic Solutions, Evonik

For several years, sustainability has been an important topic in the development and marketing of cosmetic products. However, this trend has not been as prevalent in sun care products. Film formers are indispensable in sunscreen products because they enable long-lasting and water-resistant protection against UV rays. They also play an important role in formulation by improving the aesthetics, texture and feel on the skin. Most film formers are made from synthetic polymers which do not biodegrade. We asked Evonik’s Sven Klare about film formers and the challenges of creating biodegradable sunscreen products from natural, renewable raw materials. 

What are film formers and why are they needed?

As the name suggests, film formers are substances that can create a film or layer on a surface when applied. The term “film former” is often used in different contexts. For example, film formers can be categorized as hydrophobic or hydrophilic. Hydrophobic film formers are oil thickening ingredients used in sunscreens, color cosmetics or skin care. Hydrophilic film formers are used in applications such as hair care.

In sunscreen products, film formers create a uniform film of UV filters on the skin, empowering their effective protection against harmful UV rays. When formulating a sunscreen, a film former can also improve the look and feel for consumers.  

Most film formers used in sunscreen products today are made from fossil and non-biodegradable polymers. Many companies have recognized the need to create alternatives that are sourced from renewable raw materials and are biodegradable. At Evonik, one of our latest innovations is a novel natural biodegradable and biobased film former called TEGO® FILMSTAR One MB. 

Creating biodegradable sunscreen products from natural, renewable raw materials remains a challenge. Why is this?

Sunscreen products are made up of many different components such as UV filters, emulsifiers, thickeners, emollients and film formers. The good news is that for many of these components, biobased and biodegradable alternatives are now available. Some examples include Evonik’s polyglycerol emulsifiers or enzymatic emollients. Unfortunately, it is still difficult to replace organic UV filters with such alternatives. The reason is that these organic UV filters contain aromatic molecules like aromatic esters. Natural building blocks are still not available at commercial scale. Another hurdle is that newly developed UV filters require time-consuming registrations for worldwide use. 

The majority of film formers are made from synthetic polymers which do not biodegrade. What is Evonik doing to address this challenge?

Our life sciences division at Evonik has adopted sustainability as its guiding business principle. This is reflected in some of our latest innovations like in TEGO® FILMSTAR One MB. We are pleased that this film former offers customers a biobased and biodegradable alternative. Benefits include a level of water resistance in sunscreen formulations comparable to synthetic polymers. Our innovative film former can also be easily formulated by simply adding to the oil phase. We have observed good stability and no significant thickening effect in o/w formulations. 

How do you ensure strong performance for biodegradable film formers?

Our first investigations always include in-depth studies on the formulation range with emphasis on stability, viscosity and sensory profile. In our experience, in vivo tests are still the gold standard to ensure strong performance with regards to SPF and water resistance. We also include fossil-based, non-biodegradable market benchmarks in the comparison. 

What is your strategy for film formers? Where do you see film formers in five years’ time? 

Perhaps this is clear from the name of our film former: TEGO FILMSTAR One MB! We plan to offer a full family of film formers that will address multiple applications and benefits. In five years, I see the development of in vitro tests for both SPF and water resistance with good correlation to in vivo studies, helping to find the best customized film former solution for each individual formulation at short notice. Also, I would like to see film formers based on next generation raw materials like side streams or CO₂. These are topics we are already targeting with a new program in Cosmetic Solutions at Evonik called ECOHANCE®. This program focuses on developing personal care ingredients derived from beyond biobased feedstocks.