Suspension and Its Qualities.
Suspension and Its Qualities.
Suspension and Its Qualities.
A suspension is a heterogeneous mixture in which the solute particles do not dissolve, but get
suspended throughout the bulk of the solvent, left floating around freely in the medium. The
internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical
agitation, with the use of certain excipients or suspending agents.
CLASSIFICATION OF SUSPENSION:
Oral suspension
Externally applied suspension
Parenteral suspension
2. Based on Proportion of Solid Particles:
Dilute suspension (2 to10%w/v solid)
Concentrated suspension (50%w/v solid)
3. Based on Electro Kinetic Nature of Solid:
Particles
Flocculated suspension
Deflocculated suspension
4. Based on Size of Solid Particles:
1. Must remain sufficiently homogeneous for at least the period between shaking the
container and removing the required amount.
2. Particles of the solute do not dissolve in the solvent rather they remain suspended in
bulk throughout.
3. Any suspended particles should be small and uniformly distributed.
4. They should be resistant to microbial contamination.
5. Should be chemically stable.
6. Ideal, suspension should be thixotropic.
7. Dispersed phase should settle slowly and should be readily redispersed on shaking.
8. Should not cake on settling.
9. Viscosity should be such that preparation pours easily.
10. Should be acceptable to the patient on the basis of its taste, color, and cosmetic qualities
11. The particle size of the suspension remains fairly constant throughout its long period of
undisturbed standing .