Deflocculated suspension - Definition, Preparation & Stability

In a deflocculated suspension, solid particles remain discrete and uniformly dispersed throughout the liquid medium.
While initially more uniform, these suspensions are prone to sedimentation and caking, making redispersion difficult.

Particle size reduction:
- The solid drug is milled or micronized for proper dispersion, similar to flocculated suspensions.
Wetting of particles:
- A wetting agent is used to reduce interfacial tension between the particles and the liquid medium.
Stabilization:
- A stabilizing agent (e.g., non-ionic surfactant or hydrophilic polymer) is added to prevent
- This forms a protective layer around particles, promoting repulsion and maintaining uniform dispersion.

Sedimentation and caking:
- Problem: Particles may settle and form a hard cake, making redispersion difficult.
- Solution: Increase the viscosity of the medium with thickening agents and use stabilizing agents like surfactants to prevent caking.
Particle aggregation:
- Problem: Deflocculated particles may aggregate, leading to non-uniform dispersion.
- Solution: Use stabilizing agents (e.g., surfactants or hydrophilic polymers) to maintain particle repulsion and uniform dispersion.