Water Distribution Between Particles of a Granule During Formation and Drying
At low moisture levels, termed the (pendular state), the particles are held together by lens-shaped rings of liquid. These cause adhesion because of the surface tension forces of the liquid-air interface and the hydrostatic suction pressure in the liquid bridge.
When all the air has been displaced from between the particles, the (capillary state) is reached, and the particles are held by capillary suction at the liquid-air interface, which is now only at the granule surface.
The (funicular state) represents an intermediate stage between the pendular and capillary states.
The (droplet state) this will be important in the process of granulation by spray – drying of suspension. In this state the strength of the droplet is dependent upon the surface tension of the liquid used.
Read also:
- Granulation in Pharmaceutical Industry
- Granulation End Point Determination
- Factors Affecting Dissolution of Pharmaceutical Products
Resource Person: Moath Abu Hirra
