A new addition to Lubrizol’s Carbopol line is Carbopol Aqua SF-1 OS Polymer (INCI: Acrylates copolymer). It furnishes emulsion stability and aesthetic properties to systems containing pigments and electrolytes. It is supplied as an unpreserved 30% emulsion with a use level of 1-3% (as supplied) and a recommended pH range of 6.5 to 10. Its key benefits are: excellent emulsion stabilization and suspension above pH 6.5; good thin emulsion stability; reduces level of emulsifiers needed for optimum stability and texture; highly compatible with pigments such as titanium dioxide, iron oxide and mica; enhances titanium dioxide distribution in emulsions; electrolyte tolerant; pleasant feel; and en easy to use liquid that is cold processable.
The following formula illustrates its high pigment compatibility.
|Deionized water||qs 100|
|Carbopol Aqua SF-1 OS polymer||3.00|
|Methyl glucose sesquistearate||2.50|
|PEG-20 methyl glucose sesquistearate||2.50|
|Mica (and) bismuth oxychloride (and) iron oxides (yellow pigment)||3.50|
|Mica (and) bismuth oxychloride (and) iron oxides (red pigment)||0.30|
|Mica (and) bismuth oxychloride (and) iron oxides (brown pigment)||1.00|
|Triethanolamine (50%)||qs pH 7.0|
Procedure: Mix constantly. Heat A to 70-75°C in batch tank. Heat B in separate container to same temperature and add to A. Cool to 50°C and add C. A thick emulsion is formed which passes a centrifuge test (3000 rpm/30 minutes/60°C).
Another relatively recent product comes from Corum. It is called Et-VC (INCI: 3-O-ethyl ascorbic acid). Pure vitamin C is very unstable and sensitive to oxidation that leads to discoloration and loss of efficacy. Et-VC is a stable vitamin C derivative that provides whitening effects, promotes collagen synthesis and protects skin from DNA damage. It is recommended for use in skin whitening or lightening products. It is also has applications in anti-aging products due to its ability to correct dark and age spots. Finally, Et-VC can be added to sun care products to provide more protection.
The company suggests the following claims:
- Protect DNA from UV,
- Scavenge free radicals,
- Fight photoaging,
- Stimulate collagen synthesis,
- Reduce dark spots,
- Even out skin tone, and
- Inhibit tyrosinase and TRP-2
- Use in a buffer system;
- Mix thickeners thoroughly before adding buffer solution;
- Add into the formulation below 40°C
- Low pH levels best maintain stability
- Antioxidants and chelating agents can minimize discoloration
- Store in a tightly closed container at 25°C, and protect from light, heat and moisture.
Another test was heat stability where 2% Et-VC was compared to vitamin C and another whitening agent (Arbutin) by retaining in a 45°C constant temperature oven for one month. The Et-VC solution did not change color but the other two ingredients both turned yellowish.
In an industry where formulators and consumers always want to know new improvements over existing chemistry can help companies boost market share.
Harvey M. Fishman
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.