disperse systems and suspensions

Question 1

what are the advantages of solution

Answer 1

• heterogenous
• mixing/handling
• dosing
• patient acceptability

Question 2

disadvantages of solution

Answer 2

• lack of chem, microbiological and physical stability
• patient unacceptablity

Question 3

meaning of hydrophobic and lipophilic

Answer 3

tends to dissolve in lipids

Question 4

meaning of hydrophilic and lipophobic

Answer 4

tend to dissolve in aqueous systems

Question 5

what is a disperse system

Answer 5

one component (the dispersed phase) is dispersed through the other (the continuous phase)

Question 6

do the phases in a disperse system change

Answer 6

no

Question 7

do the phases in a solution change

Answer 7

yes

Question 8

what is a solid dispersed in a solid called

Answer 8

solid suspension

Question 9

what is a liquid dispersed in a solid called

Answer 9

solid emulsion

Question 10

what is a gas dispersed in a solid called

Answer 10

solid foam

Question 11

what is a solid dispersed in a liquid called

Answer 11

sol, suspension

Question 12

what is a liquid dispersed in a liquid called

Answer 12

emulsion

Question 13

what is a solid dispersed in a gas called

Answer 13

solid aerosol

Question 14

what is a gas dispersed in a liquid called

Answer 14

a foam

Question 15

what is a liquid dispersed in a gas called

Answer 15

liquid aerosol

Question 16

can a gas be dispersed in a gas

Answer 16

no

Question 17

what does lyophobic mean

Answer 17

has aversion to the solvent type

Question 18

what does lyophilic mean

Answer 18

has an affinity for the solvent type

Question 19

what influences physical and chemical behaviour of suspension

Answer 19

particle size

Question 20

when would a suspension be optically clear and not cloudy

Answer 20

when the size of the particles in within the colloidal range

Question 21

advantages of suspensions

Answer 21

• formulate API with low solubility in continuous phase
• patient acceptability
• drugs that have unpleasant taste in soluble form can be made insoluble
• increased absorption in oral suspensions
• stability of drug increased
• can modify drug release

Question 22

disadvantages of suspension

Answer 22

active ingredient can settle at bottom of bottle

Question 23

what can change the behaviour of solid particles in suspension

Answer 23

excipients

Question 24

how does sodium chloride at low/medium concentration impact the electrical double layers

Answer 24

it affects the diffuse layer

as their is easier neutralisation of remaining surface change on particle

Question 25

how does sodium chloride at high concentration affect the electrical double layer

Answer 25

it affects the diffuse and fixed layer

Question 26

when can particles in suspensions agglomerate/aggregate

Answer 26

when - exposed to heat - shaken vigorously - added to other solutions (esp salts)

Question 27

What forces do particles have in a solution?

Answer 27

Both forces of attraction and repulsion

Question 28

What happens to the repelling force as two particles approach each other?

Answer 28

The repelling force gets stronger

Question 29

What effect does vigorous mixing have in a colloidal suspension?

Answer 29

It forces particles together, making them attracted and can start to coagulate

Question 30

What changes when conditions change in a colloidal system?

Answer 30

The double layer changes

Question 31

Fill in the blank: In a colloidal suspension, vigorous mixing can lead to _______.

Answer 31

coagulation

Question 32

True or False: In a solution, particles only experience forces of attraction.

Answer 32

False