RoA - Suspensions Flashcards
What is the rate of absorption ?
Lower that solution
When is dose uniformity assured ?
When suspension is homogenous
Excipients - sweeteners, flavours, colours
Sucrose
Excipients - preservatives (antimicrobial)
Benzoin acid
Excipients - buffers
Ionic so affect flocculation behaviour
Excipients - Suspending agents (viscosity modifiers)
Reduce particle sedimentation
Excipients - chemical stabilisers
Improve stability
Excipients - wetting agents
Decrease interfacial tension
Excipients - flocculation modifiers
Ionic materials
Eg: NaCl, CaCl2
What does DLVO theory predict?
If particles will coalesce and settle
If particles will remain homogenibly dispersed
What suspensions does DLVO theory explain?
Colloidal suspensions
What type of movement do particles undergo?
Bownian motion - irregular movement within the medium
Sedimentation (decrease size, decrease sedimentation)
How to reduce sedimentation rate?
Decrease particle size
Decrease particle density
Increase medium viscosity
Increase temperature
How can you ensure a suspension is stable throughout its shelf life?
Sedimentation must be minimum and easily re-dispersed
Visual assessment upon shaking
