Suspensions (exam 2)

Question 1

dispersed system

Answer 1

liquid preperation containing undissolved or immiscible drug in a vehicle

Question 2

phases in a suspension

Answer 2

dispersed phase
dispersing phase/medium (vehicle)

Question 3

label for suspensions

Answer 3

shake well

Question 4

coarse dispersions

Answer 4

contain large particles
ex: suspensions, emulsions

Question 5

fine dispersions

Answer 5

contain small particles
ex: magmas, gels

Question 6

suspensions are liquid preparations containing _________________ in a liquid phase in which particles are ___________________

Answer 6

solid drug particles dispersed

not soluble

Question 7

pharmaceutical suspensions has to possess

Answer 7

therapeutic efficacy
chemical stability
permanency of preparation
esthetic appeal

Question 8

routes of administration for suspensions

Answer 8

oral
topical
ophthalmic
parenteral

Question 9

reasons to formulate a suspension

Answer 9

when a drug is insoluble
when a drug is unstable in solution
when the taste is bad, needs to be overcome

Question 10

suspensions contain

Answer 10

large solid drug particles

Question 11

sedimentation

Answer 11

particles tend to settle, redisperse upon shaking

Question 12

__________________ is very important to the accurate administration of doses

Answer 12

uniform redistribution

Question 13

caking of suspension

Answer 13

rigid cohesion of particles that resists breakdown upon shaking

Question 14

what can prevent caking?

how?

Answer 14

flocculation

enhances particle dispersability

Question 15

what type of particles produce more stable suspensions?

Answer 15

barrel shaped particles

Question 16

flocs resist complete settling, but flocculated particles ________________ than fine particles

Answer 16

settle faster

Question 17

stokes equation says sedimentation rate can be decreased by

Answer 17

reduce the particles size (dispersed phase)
increase the viscosity of the suspension (dispersion medium)

Question 18

zeta potential

Answer 18

voltage difference between ions in tightly bund layer and electroneutral region

Question 19

the magnitude of the zeta potential gives an indication of

Answer 19

the stability of the dispersion system

Question 20

suspension with zeta potential between -30mV and +30mV

Answer 20

unstable

Question 21

suspension with zeta potential more than +30mV or less than -30mV

Answer 21

stable

Question 22

micropulverization

Answer 22

for oral and topical solutions
mill and beaters produce fine drug power

Question 23

grinding

Answer 23

for parenteral and ophthalmic solutions
rotating hammers/pins produce very fine particles

Question 24

spray drying

Answer 24

cone shaped apparatus rapidly dries and produces very very small particles

Question 25

compounding mechanism to decrease particle size

Answer 25

trituration

Question 26

suspensions for neonates should not include

Answer 26

preservatives alcohol color flavors

Question 27

which type of powder requires a wetting agent? and why?

Answer 27

hydrophobic powders not wet by water

Question 28

how does wetting agents work?

Answer 28

disperse air in the particles disperse particles allow penetration of dispersion medium into powder

Question 29

examples of wetting agents (2-5%)

Answer 29

alcohol glycerin propylene glycol surfactants

Question 30

suspending agents are added to

Answer 30

thicken the dispersion medium

Question 31

examples of suspending agents (1%)

Answer 31

carboxymethylcellulose methylcellulose microcrystalline cellulose polyvinyl pyrrolidone

Question 32

examples of flocculating agents

Answer 32

clays electrolytes nonionic surfactants ionic surfactants

Question 33

why is a portion of the vehicle used to wash mixing equipment?

Answer 33

to ensure correct drug concentration in the suspension

Question 34

suspensions are physically

Answer 34

unstable systems

Question 35

beyond use date when stability is not known

Answer 35

14 days

Question 36

packaging and storage of suspensions

Answer 36

wide mouth containers adequate airspace above liquid tight, light resistant container protect from freezing and excessive heat stored in fridge

Question 37

types of suspensions

Answer 37

ready to use form of suspensions dry powders for oral suspension extemporaneously compounded suspensions

Question 38

usual adult dose of an oral suspension is

Answer 38

5 ml (1 tsp)

Question 39

pediatric dosing of suspension is

Answer 39

dose calibrated number of drops