The benefits of this ingredient include:
- High thickening efficiency in sulfate- based or sulfate-free surfactant systems;
- Good suspension properties in low to medium surfactants (6 to 13% active surfactants);
- Superior clarity for pH >6.3 with high tolerance toward salt;
- Enhanced flash foam and foam volume with high foam whiteness and elasticity;
- Pleasant in-use feel and clean rinse properties;
- Good compatibility with cationic polymers; and
- Liquid form, which makes it suitable for cold processing.
When formulating with Rheomer 33, the recommended use level is 2-3% active or 6.5-11% as supplied. The recommended pH is 4-11, but for optimal clarity, pH >6.3 is best. Where clarity is not desired, the pH can be adjusted below 6 after neutralizing with an alkaline solution. Suspension properties usually increase below pH 6.
Some suggested products which make use of Rheomer’s suspending ability are a pearlescent body wash with suspended mica, a clear liquid hand soap with emollient capsules, a vegetable oil moisturizing shower gel, and a sulfate free facial wash with exfoliating beads. An example of a body wash follows.
Crystal Clear Exfoliating Body Wash
|Sodium laureth sulfate||5.0|
|Sodium lauryl sulfate||3.0|
|Sodium Hydroxide (15%)||q.s.|
|Water||q.s. to 100|
No heating is necessary.
Another Idea from Rhodia
A companion product to Rheomer 33 could be Miracare SLB (INCI: Water, sodium trideth sulfate, sodium lauryl amphoacetate, cocamide MEA). This surfactant blend allows formulators to suspend high levels of conditioning oils, generate rich, dense foam even in the presence of oil, incorporate high levels of perfumes and essential oils, create lotion-like textures, suspend insoluble actives such as triclosan and incorporate high molecular weight polymers.
The ease of use is stressed because standard equipment can be used, only low shear mixing is needed, no heat is needed, the single surfactant addition produces a flowable liquid, and oils and fragrances can be added anytime during or after the structuring process. Prepare in a three steps by adding water to Miracare ME, add the oil phase, and then add salt and adjust the pH. Mild agitation is needed about 150 rpm. A sample formula follows:
|50% citric acid solution(to pH 5.8 to 6.2)||1.00|
|Water||q.s. to 100|
Harvey Fishman has a consulting firm in Wanaque, NJ, specializing in cosmetic formulations and new product ideas, offering tested finished products. He has more than 30 years of experience and has been director of research at Bonat, Nestlé LeMur and Turner Hall. He welcomes descriptive literature from suppliers and bench chemists and others in the field.