Korean trends continue to influence cosmetic formulationsBy Martin Gunson, Business Unit Manager – Personal Care at OQEMA - 01/03/2018
Our more traditional approach of western formulation is also being challenged by the novel rheology many of these products exhibit. Key brand leaders such as Shiseido, Amore Pacific, Kosé and Pola all play with the rheological characteristics of their newest formulas to create memory gels that flow seamlessly back to their original form in an “as if by magic” way, or create products that look like a gel yet behave like a liquid that can be sprayed to leave a light enhanced skin feel.
The personal care division of OQEMA, Europe’s newest speciality chemicals distribution company, has been monitoring these trends and, by reviewing the ingredient listings of many of the cutting edge Korean skincare products, OQEMA has identified that many of the formulations contain a novel ingredient manufactured by the Japanese chemicals company ADEKA Corporation: PEG-240/HDI Copolymer Bis-Decyltetradedeth-20-Ether.
What is PEG-240/HDI Copolymer Bis-Decyltetradedeth-20-Ether?
In summary, this is a non-ionic urethane polymer, that forms a water gel and can maintain the viscosity of the product, even in the presence of organic and inorganic salts, to enable thickening and thixotropic effects to the associated formulation.
The hydrophobic tails of the polymer form micelles in the aqueous system, whilst the hydrophilic centre creates a network or matrix plugging across the aqueous phase linking into other micelles, thus gelling the water to create stable framework (Figure 3). The resultant gel remains solid, but breaks easily, dependant on the level of polymer present, to flow and reform quickly. This characteristic enables formulators to develop interesting and novel characteristics in the rheology of the end product.
It also reduces the likelihood of air entrainment, a problem often associated with gel manufacture, as any bubbles formed during the manufacturing process are able to easily flow upwards and burst at the surface, which then reforms to create a smooth layer. PEG- 240/HDI Copolymer Bis-Decyltetradeceth-20-Ether can produce gel viscosities of over 100,000mPa with additions of between 1.5-2% solid without adversely affecting this characteristic (Figure 4).
The non-ionic nature of urethane polymer enables higher addition levels of organic and inorganic salts than would be possible with a more traditional carbomer based system. This enables higher inclusion rates of active ingredients to be considered and achieved.
QEMA found that PEG- 240/HDI Copolymer Bis-Decyltetradeceth-20-Ether is most tolerant of surfactants or amphipathic substances having hydrophobic and hydrophilic groups which are delocalized and do not contain a hydrocarbon chain, examples would be Poloxamer, Polyquaternium-6 and PVP. Surfactants containing delocalized groups and hydrocarbon chains can be used up to 5% without significantly disrupting the gel.
A number of formulations with novel rheology are already available from OQEMA Ltd. The Personal Care team of OQEMA Europe are on a journey to further evolve and develop the customer experience. We will drive synergies and expertise in our key locations, becoming evermore the key European partner for product innovation and value.