Namely
Hydrated silica or silicic acid is mainly used in toothpastes as a gentle abrasive agent. It enhances brushing action and acts on dental plaque and unsightly discolouration.
Its functions (INCI)
Abrasive : Removes materials from the surface of the body, helps clean teeth and improves shine.
Absorbent : Absorbs water (or oil) in dissolved or fine form
Anticaking : Helps ensure the fluidity of solid particles and limit their agglomeration in powder cosmetic products or hard mass cosmetics.
Bulking : Reduces apparent cosmetics density.
Opacifying : Reduces transparency or translucency of cosmetics
Viscosity controlling : Increases or decreases the viscosity of cosmetics