Precipitated silica is a form of silica produced by precipitation. This glidant is a precipitated silica that fills in any irregularities in the other particles of your formulation. This creates a smooth surface that: 
1. Prevents adhesion between particles of different ingredients.
2. Prevents formula from sticking to punch face.
3. Turns sliding friction into rolling friction, letting particles glide past each other for better fluidity.  Better flow means more consistent die fill and less variation in tablet weight.

Precipitated silica