Glidant

A glidant is a substance that is added to a powder to improve its flowability. A glidant will only work at a certain range of concentrations. Above a certain concentration, the glidant will in fact function to inhibit flowability.

In tablet manufacture, glidants are usually added just prior to compression.

Examples

Examples of glidants include magnesium stearate, Aerosil (colloidal silicon dioxide), starch and talc.

Mechanism of Action

A Glidant's effect is due to a counter-action to factors resulting in poor flowability of powders. For instance, correcting surface irregularity, reducing interparticular friction & decreasing surface charge. The result is a decrease in the angle of repose which is an indication of an enhanced powder's flowability.