When it comes to classes of cosmetic ingredients, perhaps fillers have the most misleading name. Fillers are defined as inert ingredients that add bulk and texture to a cosmetic product, but they often have many functional benefits too. Fillers can also be used to adjust sensorial properties and influence the application behavior of color cosmetics and skin care formulations like lipstick, lotion, mascara, pressed or loose powders, and foundation. Functional fillers can further enhance formulations by effecting viscosity, hardness, and skin feel while contributing to coverage and soft focus properties.
In sticks or oil/wax bases fillers reduce the oily feel and help to balance pigment level across shades.
- Lipsticks 2 – 10%
- Foundation Sticks 5 – 20%
- Stick/Cream Eye Shadow 7 – 25%
- Cream Blush 5 – 15%
Fillers can be used in emulsion based systems to reduce drying time and deliver body in mascara and to improve skin feel and viscosity in foundations, as well as providing a way to balance pigment levels across shades.
- Mascara 2 – 7%
- Foundation 2 – 10%
- Liquid Eyeliner 2 – 10%
Pressed powders often contain high levels of fillers to influence texture, compressibility, and payoff.
- Face powders 5 – 60%
- Eye shadow powder 5 – 30%
Natural Mica – Magnesium aluminum silicate. This is a soft, translucent powder with excellent binding properties. It has a smooth feel due to natural platelet structure. Sericite mica has a matte appearance while muscovite mica has a pearlescent appearance. Sericite has better compressibility that muscovite mica. Sericite mica properties are similar to talc and is used as a replacement in talc-free formulations.
Synthetic Mica – Synthetic fluorophlogopite. Properties similar to natural mica, more clean mass tone and low heavy metals content.
Talc and Treated Talc – Magnesium silicate. Light grey to white with a soft feel. Larger particle sizes have a higher degree of transparency but poor compressibility. Various particle sizes are often blended to optimize compression qualities in pressed powders. Talc can be surface treated to improve compressibility, optimize dispersion in formulation, enhance sensory attributes, and increase adhesion (long-wear attributes) to the skin. Two common examples of surface treatments include:
- Disodium stearoyl glutamate – Enhances perception of moisturization, improved compressibility, and good compatibility with skin.
- Dimethicone – Long wear and waterproofing properties. Improves dispersion and compatibility with silicones used in emulsions for foundations and other liquid makeup.