Cosphaderm® Absolute is a blend of three established humectant actives in optimally aligned concentrations. Using Cosphaderm® Absolute helps to hydrate the skin and improve the skin’s barrier function while reducing the water activity of a formulation. The lower the water activity of a formulation, the less antimicrobials
need to be used for preservation.
With sodium lactate and betaine, Cosphaderm® Absolute provides two skin-own substances of the natural moisturizing factors (NMF), which ensure the maintenance of the moisture content in the skin. In addition to its solubilizing function, the multifunctional propanediol promotes the moisturizing effect of the blend. The three substances share a strong hygroscopicity, which lowers the water activity and thus the availability of water for microorganisms at the recommended use concentrations. Thus, the natural blend combines a safe antimicrobial mode of action with skin barrier-enhancing properties, providing an innovative, alternative npreservation strategy that meets market needs and current trends of the cosmetics industry.
Strengthening the skin barrier
Due to its special structure, on the one hand a healthy skin barrier protects the body from uncontrolled water loss, and on the other hand, from environmental influences that pose a hazard to health. A sufficient moisture content is essential for the functionality of the skin barrier and thus for healthy, well-cared skin.
Structure of the skin
The skin barrier enhancing effect of Cosphaderm® Absolute was demonstrated in a vehicle-controlled study with 14 volunteers. After two weeks of using a basic O/W emulsion with 20% Cosphaderm® Absolute twice daily, skin hydration improved by 45.6%. In addition, transepidermal water loss (TEWL), one of the key parameters used to assess the skin barrier, was reduced by 11.4%.
Fig.: Vehicle-controlled subject study on the influence of Cosphaderm® Absolute on the skin barrier.
* = statistically significant (vs. untreated); p-value ≤ 0.05; error bars indicate the standard deviation of the mean
Antimicrobial effect thanks to water activity reduction
Unlike the water content of a formulation, which specifies the total volume of water including molecularly bound water, water activity (aw) is a measure of the “free”, unbound water within a product. This unbound water is freely accessible for microorganisms and they can use it for reproduction. Conversely, restricting the availability of unbound water causes deterioration of microbial growth conditions
Pure water has an aw value of 1. Adding small, hydrophilic molecules binds water on the basis of intermolecular interactions and reduces the aw value accordingly. In order to reduce the aw value of a skincare emulsion to such an extent that microorganisms are impaired in their ability to grow, high amounts of water-binding substances are needed. However, such high amounts exceed the recommended concentrations of individual ingredients and can have a negative impact on the formulation‘s sensory properties. Cosphaderm® Absolute contains a combination of the substances sodium lactate, propanediol and betaine in an ideally tuned ratio. As a result, using this blend creates stable formulations with efficient aw reduction and excellent skin sensation.
The antimicrobial effect of Cosphaderm® Absolute has been proven in numerous challenge tests. It can be excellently combined with other Cosphaderm® Multifunctionals, guaranteeing mild and skin-friendly, yet remarkably good antimicrobial protection for formulations. Here you can see examples of the excellent results obtained in a challenge test:
