The human skin is a natural protective shield that is exposed to UV radiation, air pollution and unhealthy lifestyles such as smoking and alcohol consumption. These external influences lead to oxidative stress and accelerate skin ageing. Cosmetic formulations are also affected by oxidative influences, meaning that the oils they contain can become rancid. However, these processes can be significantly inhibited by using suitable antioxidants. As a natural component of many plants, antioxidants neutralise free radicals with their radical scavenging or electron donor properties, rendering them harmless. Cosphatec, a leading international raw materials manufacturer based in Hamburg, has set itself the task of developing sustainable and innovative solutions for modern natural cosmetics. With a focus on natural and skin-friendly ingredients, Cosphatec offers more than 70 products that fulfil the current standards of natural cosmetics and offer additional positive benefits for the formulation or the skin in addition to product protection.

This year, the company has launched a highly effective antioxidant blend: Cosphaderm® Tocopharin.

Double Protection Mechanism thanks to Effective Antioxidant Combination

Cosphaderm® Tocopharin is a blend that combines the protection of the oil phase of the formulation with a positive influence on oxidation processes in the skin. Consisting of the natural antioxidants tocopherol and carnosic acid dissolved in sunflower oil, Cosphatec's blend is easy to use and does not affect the smell or colour of the formulation. The included tocopherol blend contains a high proportion of γ-tocopherol and thus ensures excellent protection of the formulation. The carnosic acid extracted from rosemary (Rosmarinus Officinalis) not only supports the tocopherol in protecting the oil phase, but also has a strong effect in protecting the skin from oxidative processes. Of course, the blend is COSMOS and NATRUE compliant.

Protection Against UV-Induced Oxidation Processes with Natural Carnosic Acid

In order to substantiate the antioxidant effect of Cosphaderm® Tocopharin in the skin, an in vitro study was conducted in which the amount of reactive oxygen species in human keratinocytes was measured. These skin cells were incubated with the test substances for 24 hours, exposed to UV irradiation for induction of ROS formation and subsequent measurement of decreased ROS formation. The positive effect of Cosphaderm® Tocopharin becomes obvious in comparison to the reference materials mixed tocopherols and the synthetic standard antioxidant Butylated Hydroxytoluene (BHT), which were each used at the same concentration in the assay (Fig. 1). The synthetic antioxidant BHT and the mixed tocopherols display comparable performance at 0.003%. At the same application concentration, Cosphaderm® Tocopharin can significantly decrease the formation of ROS through UV irradiation. Compared to the untreated sample, Cosphaderm® Tocopharin can reduce the ROS level by 26%. These results confirm a striking skin-cell-protecting effect of Cosphaderm® Tocopharin against UV-induced oxidation processes.

Figure 1: Fluorometrically determined relative ROS quantity in human keratinocytes after 24-hour incubation with the test substances and subsequent two-hour UVA irradiation. Samples: untreated UVA-irradiated control (violet), BHT (red), mixed tocopherols (green), Cosphaderm® Tocopharin (blue). Statistical significance is indicated by * for p < 0.05.

Excellent Product Protection for Cosmetic Formulations

Cosmetic formulations containing oils must be protected against visual and odour impairment caused by oxidative processes. Thanks to the combination of the two antioxidant substances Tocopherol and Carnosic Acid, only low concentrations of Cosphaderm® Tocopharin starting from 0.1% are required to ensure excellent product protection. The outstanding effectiveness of Cosphaderm® Tocopharin in protecting oils against rancidity was demonstrated in Rancimat tests in comparison with the industry standard mixed tocopherols (Fig. 2). Relative change compared to untreated sunflower oil when using the antioxidants is shown. The improvement in oxidation stability with 0.2% mixed tocopherols is evident. At the same concentration, a further 25% increase in stability can be achieved with Cosphaderm® Tocopharin. At equivalent quantity of tocopherols, the influence of Carnosic Acid is clearly highlighted. The corresponding application concentration of 0.68% Cosphaderm® Tocopharin leads to a tripling of the oxidation protection performance.

Figure 2: Determination of oxidation stability via Rancimat test at 100 °C according to method §64 LFGB L13.00-38:2010-01. Relative increase in induction time compared to untreated sunflower oil by 0.2% mixed tocopherols (green), 0.2% Cosphaderm® Tocopharin (blue) or 0.68% Cosphaderm® Tocopharin (red).

Maximum Protection through Double Antioxidant Power:

If you want to provide your cosmetic formulation with the best possible protection against oxidative processes and at the same time offer active skin protection against UV damage with your product, you have found the perfect raw material in Cosphaderm® Tocopharin. The powerful antioxidant blend with the combination of rosemary-derived carnosic acid and tocopherol offers a double protection mechanism for cosmetic formulations and skin. The liquid, oil-soluble blend is easy to incorporate and is suitable for a wide range of formulations without compromising odour or colour. Cosphatec recommends a concentration of 0.1 – 0.5% for effective application.

Cosphatec GmbH
Hopfenmarkt 33
20457 Hamburg
www.cosphatec.com

Author
Annika Greupner, Junior R&D Manager
Annika.greupner@cosphatec.com