COARSE DISPERSION Flashcards
- Particle size between greater than 500 nm
- Visible under ordinary microscope
- Do not pass through filter paper
- Do not pass through semipermeable membrane
- Do not diffuse
COARSE DISPERSION
Most pharmaceutical suspensions and emulsions are
coarse dispersions
SUSPENSION
Insoluble Solid, internal
dispersed phase
SUSPENSION
liquid, external
dispersion medium
SUSPENSION
concentration of externally applied suspensions
.>20%
SUSPENSION
concentration of Parenteral suspensions
0.5 - 30%
Advantages of Pharmaceutical Suspension
Make insoluble drugs more ____
palatable
Advantages of Pharmaceutical Suspension
Provide suitable dosage form for ____ to skin and mucous membrane while retaining the grittiness of the solid particle
dermatologic materials
Advantages of Pharmaceutical Suspension
Parenteral administration of ____ drugs
water-insoluble
Characteristics of an Acceptable Suspension
Suspended material should NOT ____
settle rapidly
Characteristics of an Acceptable Suspension
Sediments do NOT for a ____
hard cake
Characteristics of an Acceptable Suspension
____ when shaken
readily dispersed
Characteristics of an Acceptable Suspension
Not too ____
viscous
Characteristics of an Acceptable Suspension
for lotions:
Easily ____
spread
Characteristics of an Acceptable Suspension
for lotions:
____ quickly
dry
Characteristics of an Acceptable Suspension
for lotions:
have acceptable ____ and ____
color & odor
Physical Stability of Suspensions
Particles do not ____
aggregate
Physical Stability of Suspensions
They remain ____ throughout.
uniformly distributed
Physical Stability of Suspensions
Easily resuspended by ____
moderate agitation
light fluffy conglomerates held by weak van der Waals forces
flocs / floccules
Properties of Suspended Particles
Tend to ____
flocculate
flocs or floccules are held by
weak van der waals forces
- particles adhere by stronger forces
- leads to CAKING
aggregates
growth and fusing of aggregates
caking
FLOCCU OR DEFLOCCU
Sediments are loosely packed
(FLOCS)
FLOCCULATED
FLOCCU OR DEFLOCCU
Sediment is closely packed (AGGREGATES) and forms a hard cake
DEFLOCCU
FLOCCU OR DEFLOCCU
Sediment rapidly forms
FLOCCU
FLOCCU or DEFLOCCU
Sediments slowly forms
DEFLOCCU
FLOCCU or DEFLOCCU
High sedimentation rate
(settles rapidly)
FLOCCU
FLOCCU or DEFLOCCU
Low sedimentation rate
(settles slowly)
DEFLOCCU
FLOCCU or DEFLOCCU
Easily redispersed when shaken
FLOCCU
FLOCCU or DEFLOCCU
Difficult to redisperse
DEFLOCCU