Flocculated and deflocculated suspensions are two types of colloidal dispersions, typically seen in the pharmaceutical field, where solid particles are dispersed in a liquid medium.


1. Flocculated Suspension:

  • In a flocculated suspension, the dispersed particles are aggregated to form loose, light structures called flocs or floccules.
  • The particles are loosely bound, forming larger aggregates, which settle faster but are easily re-dispersed by gentle shaking.
  • The sediment formed is loosely packed, and the suspension appears cloudy but has a uniform consistency.
  • Advantages:
    • Easier redispersion after sedimentation.
    • The suspension has good flow properties and maintains physical stability.

2. Deflocculated Suspension:

  • In a deflocculated suspension, the particles exist as individual, separate entities.
  • Due to their small size, they settle slowly and compact tightly at the bottom, forming a hard, dense sediment called a cake.
  • This caking makes it difficult to re-disperse the suspension, leading to uneven dosing.
  • The suspension may initially appear clearer but with sedimentation, a compact layer forms that is hard to break.

In summary, flocculated suspensions are easier to re-disperse compared to deflocculated suspensions, which may undergo caking, making them challenging to handle.