SUN CARE
29
Sun protection: formulation as easy as winking
Lars Jung, Ev Suess – Symrise AG
The development of a new sunscreen product requires the consideration of several aspects. In addition to usual demands for personal
care products, like stability and sensorial performance, there are countries or regional specific regulations concerning safety aspects to follow and the selection of the UV filters and their use level underlies certain limitations. The effective protection against UVA and UVB rays and the achievement of the claimed SPF needs to be substantiated by in vivo SPF tests. Consumers can of course expect that their
sunscreen products are safe, comply with the regulations; provide effective protection against sunlight radiation. Moreover, they desire convenient products which are easy to use and to apply. An appealing sun care product should be instantly absorbed, non-greasy or non- sticky. Usually, it should provide also additional benefits like e.g. moisturising, refreshing or anti- ageing properties.
Formulating a strategy Before starting the development work, formulators have to set up the key requirements for the sun protection product: The target market and the definition of the
desired SPF and the related UVA protection are the basis for all further considerations. The choice of the UV filters is crucial for the effectiveness of the sunscreen product. A common approach to comply with regulatory requirements regarding efficacy and UVA protection in most countries is to use at least one UVB and one UVA filter. UVA filters and the combination of oil and water soluble UVB filters might significantly help to improve the SPF.
1.0 0.8 0.6 0.4 0.2 0.0
UV-C UV-B UV-A II ABSTRACT
The formulation of sun protection products can become a difficult job for the formulator. Selecting the right UV filter combination to achieve broad spectrum protection, adjusting the use levels of each UV filter to reach the desired SPF (sun protection factor) while complying with all regulatory demands and providing sufficient stability to the formulation are only a few of the challenges. And these are just the requirements for
providing a sun care product, doing what it should do - protect the skin from UV radiation. The skin-feel and the textures for different application types have not yet been taken into consideration. A sun care product with an SPF 30,
matching all requirements and providing a comfortable skin-feel can easily contain 20 to 25 different ingredients. Neo Heliopan® Flat1
(INCI: Homosalate,
Octocrylene, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Butyl Methoxydibenzoylmethane, Ethylhexyl Salicylate) offers a combination of UVA and UVB filters providing a broad spectrum
All used UV filters have to be allowed
in the country or region where the finished product will be marketed. In the EU, Mercosur, China or ASEAN States3
, sunscreen products
are treated as cosmetics. In some countries, like Japan or Taiwan, they are regulated as Functional or Medicated Cosmetics. Whereas in other countries they are legislated as over
UV-A I
protection from ultraviolet radiation. The blend uniformly absorbs solar radiation ranging from 300 to 360nm and therefore provides optimal protection against harmful UVA and UVB rays. The simple adjustment of the use level enables the manufacture of sunscreen products, such as lotions, creams, sprays and oils with sun protection factors from 6 to 50+ without the need to add additional UV filters. The liquid blend is composed in a way that
crystalline UV filters stay solubilised down to -20°C, which makes it also suitable for cold/ cold processes which save time and energy in the manufacturing process and avoids the handling of powdered UV filters. In combination with SymEffectTM
Varytex2
(INCI: Propanediol Dicaprylate/Caprate, Triisononanoin, Diisopropyl Adipate, Caprylic/ Capric Triglyceride, Stearyl Heptanoate, Glyceryl Oleate Citrate, Cetearyl Nonanoate, Stearyl Caprylate), a well-balanced selection of oil components and an effective O/W emulsifier, the creation of sun care products with different textures, from sprays to creams becomes even easier.
the counter (OTC) drugs, as in the USA, Canada and Australia, what conversely also demands individual approaches to fulfil the demanded quality management. It is advised to also check the legal status
280 290 300 310 320 330 340 350 Wavelenght in nm Figure 1: UV Absorbance Curve NeoHeliopan® Flat in 10 ml/l Isopropanol.
www.personalcaremagazine.com 360 370 380 390 400
of each UV filter for each country where the finished formulation will be sold before formulation work starts. Even for globally approved sunscreen filters, the maximum levels permitted to be used may differ significantly. Once the legislation topics are clarified and the right UV filters are selected, the next important criteria need to be set. Today, UV filters are used in a huge variety of cosmetic products. There are the traditional beach products but also face care products like daily wear or tinted products frequently claim a SPF. Specific target groups like kids or baby products, products for outdoor activities and products for specific ethnic demands can require specific application forms. The question if a product is displayed in a bottle, a jar, a tube, a dispenser, an aerosol or a pump spray requires also different textures and basic formulations. More and more sunscreen
May 2021 PERSONAL CARE
Absorbance E 1%/1cm
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