Magnesium Aluminum Silicate (MAS) is a white, highly purified mineral derived from smectite clays. It serves as stabilizing, suspending, and emulsifying agent for cosmetic formulations. In addition, it has a high surface area and can act as an adsorbent, eliminating dirt and impurities.
MAS is a helpful ingredient for acidic preparations, thanks to high acid compatibility. In addition, it allows controlling viscosity and rheology of formulations, especially in creams, while improving sensory properties.
Smectite clays are tasteless and odorless in their natural state. However, they do have the ability to absorb certain flavors and perfumes. This property helps mask some bitter, medicinal flavors and prolongs perfume fragrances. In addition, the inclusion of magnesium aluminum silicate in skincare formulas results in more palatable, stable products in combination with some ingredients.
A Magnesium Aluminum Silicate/water dispersion has a high gel strength to viscosity ratio. It is very flexible in the rheological aspect allowing to achieve the performance requirements of a specific application. This can be accomplished by combining the MAS with various natural or synthetic organic gums such as Xanthan Gum, Cellulosics, or Acrylic Polymers. In addition, its colloidal network of particles develops an internal structure capable of providing an excellent suspension of fine particles.
Magnesium Aluminum Silicate functions as a protective colloid that surrounds oil droplets and keeps them dispersed by increasing the viscosity of the formulation. Smectite clays' network of particles insulates the oil, preventing coalescing and stabilizing emulsions. It stabilizes both oil-in-water and water-in-oil emulsions at low concentrations. MAS's colloidal structure holds particles separate and suspended, even at high temperatures. It complements surfactants by improving the skincare product's spreadability, viscosity, and film-forming properties.