In its work, presented at the Stratum Corneum VIII conference by Jean-Luc Garaud, Dow Corning identified a new route to obtain low particle adhesion performance in-vitro delivered from a cosmetic formulation.
According to Garaud, the effect was observed into diversified chassis, indicating potential to be applied to different skin care product types.
“Avoiding the use of high amounts of solid particulates removes barriers in terms of sensory, visual appearance or dilution-in-formulation challenges,” he says, adding that future work will include further demonstrating performance in vivo.
Pollution concern
Pollution has become a growing concern among consumers due to its impact on the skin, causing damage and contributing to ageing.
There have been a number of cosmetic products launched featuring anti-pollution claims, focusing on treating the symptoms only.
Dow Corning believes that this new research demonstrating the ability of silicone specialties to form a film preventing the aggression from reaching skin, will be of further interest.
In its research, technologies were screened through water contact angle measurements on thin cosmetic coatings, prepared either on glass or collagen.
Carbon black was selected as a pollution particle equivalent and adhesion was assessed on coatings applied on collagen. Scanning electron microscopy (SEM) was also leveraged to evaluate in parallel the surface aspect of the coatings generated.
Results
Goniometer results on neat systems showed that the inclusion of solid particulates within a silicone film-former matrix could lead to an increase in water contact angle value.
Garaud says best results were obtained using a bi-modal particle size distribution, through a combination of micrometer- and nanometer-scale particulates.
However, the effect was lost upon reducing the solid particulates density within the film matrix, resulting from formulating the technology into a cosmetic cream.
Particle adhesion testing showed performance could be obtained from solid particulate-free systems. Associated SEM measurements confirmed the importance of the creation of a micro-roughened structure to obtain satisfactory results.
Combining the two sets of results led to proposing a new mechanism enabling low particle adhesion from a technology delivered from a cosmetic formulation.
“It builds on adjusting the interaction between the silicone technology and the other formulation ingredients, so that a micro-roughened surface is created after application,” says the Dow Corning data.
“The effect was observed in three different chassis (hydrogel, oil-in-water and water-in-oil emulsions), representative of typical cosmetic skin care systems.”