Do rinse-off cleansers benefit from adding silicones?
I tried adding 0.5% Dow 8170 amodimethicone emulsion (for 0.1% net amodimethicone content) and sometimes I felt some slight improvement and better afterfeel. I’ll need to conduct some blind tests to confirm that.
Are silicones beneficial in skin cleansers?
Literature doesn’t say much about it:Cosmetic Usage of Silicone FluidsThere are several cosmetic usages of silicone fluids, as shown in Table 2.8. Silicone fluids are used in low concentrations in many applications. The reason for this relates to their hydrophobicity, which results in their deposition on skin.
This deposition has many desirable properties. Silicone fluids can be used to remove tacky organic products, like soaps, from the skin, while providing lubrication and a skin feel that is highly desirable.While the mechanism of use is the same and independent of the viscosity chosen, the properties of the cosmetic product made with the different viscosity silicones are quite different. The skin feel can be altered significantly by picking the proper silicone fluid. Higher molecular weight products have an oilier feel on the skin, while lower viscosity products have a dryer feel on the skin. Silicone fluids with viscosity over 200 cSt are not soluble in alcohols, while products with lower viscosity are alcohol-soluble.One key limitation on the use of silicone fluids in formulation is the fact that the concentration needs to be kept very low. The very same insolubility that is a consequence of the hydrophobicity and drives the deposition places severe limitations on the useful concentrations. If too much silicone fluid is used, it will result in a product that will separate, have difficulty foaming and lack the most basic aesthetics for a personal care product. Skilled formulation helps, but modification of the product and introducing organofunctionality into the product is a good way to overcome the shortcomings of silicone fluids.
Table 2.8. Cosmetic Use of Silicone FluidsSkin Cleanser Lubricity 0.1–0.5%Wetting 0.1%
(pages 48-49)ConclusionA new emulsion technology developed and patented by Dow Corning has been evaluated for improving the sensory profile of shower gel products. The positive impacts are on both the foam quality and the dry skin after-feel. It has been found that the best emulsion has a low particle size and a very high internal linear polymer viscosity, a combination that can only be produced using this new technology.The mechanism for this performance has been identified: an improved deposition with a low particle size combined with a lower sensory threshold due to a high internal polymer viscosity. The deposition evel has been quantified to be approximately 0.0023 mg/cm2.
In addition, it has been demonstrated that sensory performance is expected to be increasingly perceivable with use frequency of the shower gels, and also that the silicone deposited from the shower gel could potentially also protect the skin during the time necessary for rebuilding its natural barrier.
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