Methods of formulation

Question 1

To be classified as a colloid, the particles must not settle under gravity. True or false?

Answer 1

True

Question 2

What is the difference between a disperse system, a colloidal suspension and a coarse suspension?

Answer 2

a dispersed system is made from a dispersed/internal phase (particles or droplets) dispersed in another component ( continuous phase), a colloidal suspension is used between 1nm- 1um & coarse suspension above 1um

Question 3

What are the 3 purification methods of disperse systems?

Answer 3

dialysis, ultrafiltration & electrodialysis

Question 4

What is a sol?

Answer 4

A colloid suspension of solid particles in a liquid

Question 5

An emulsion is a mixture of two solids. True or false?

Answer 5

False

Two liquids

Question 6

How is a foam formed?

Answer 6

when many gas particles are trapped in a liquid or solid

Question 7

An aerosol contains small particles of liquid or solid dispersed in a gas, True or false?

Answer 7

True

Question 8

What is meant by a lyophobic colloid?

Answer 8

solvent hating

Question 9

What is meant by a lyophilic colloid?

Answer 9

Solvent loving

Question 10

Lyophilic sols exhibit low viscosity. True or false?

Answer 10

False

High viscosity

Question 11

Are the particles in a lyophilic sol symmetrical or asymmetrical?

Answer 11

asymmetrical

Question 12

Lyophilic particles are stable to addition of electrolytes. True or false?

Answer 12

True

Question 13

Lyophobic sols exhibit high viscosity. True or false?

Answer 13

False

Low viscosity

Question 14

Lyophobic sols contain symmetrical particles. True or false?

Answer 14

True

Question 15

Lyophobic sols are sensitive to the addition of electrolytes. True or false?

Answer 15

True

Question 16

How are lyophobic dispersion systems formed?

Answer 16

The dispersion of oil in water

Question 17

What is meant by dispersion?

Answer 17

The breakdown of coarse material by colloid mills or ultrasonic treatment

Question 18

What is the stability of an emulsion assessed by and how can it be increased?

Answer 18

visualization & by monitoring particle size over time. Can be increased by reducing droplet size, decreasing density differences & increasing viscosity of continuous phase

Question 19

Condensation involves the slow production of a supersaturated solution of the colloidal material under conditions that cause formation of colloidal particles and not a precipitate. True or false?

Answer 19

False

Fast production

Question 20

What are random zig zag collisions a result of?

Answer 20

X

Question 21

At what size will particles sediment under gravity?

Answer 21

0.5 micrometres or more

Question 22

Particles less than 0.5 micrometres have to be sedimented by centrifugation. True or false?

Answer 22

True

Question 23

What are flocs?

Answer 23

Aggregates with an open structure

Question 24

Majority of gels are formed by aggregation of colloidal sol particles. True or false?

Answer 24

True

Question 25

What is a gel containing no liquid called?

Answer 25

A xerogel composed of charged particles and form gels by flocculation

Question 26

Bentonite is a clay. What are clays composed of and how do they turn into gels?

Answer 26

Composed of charged particles and form gels by flocculation

Question 27

Which type of bonds hold type 1 gels together?

Answer 27

Covalent

Question 28

Which type of bonds hold type 2 gels together?

Answer 28

Weak bonds like H bonds

Question 29

Type 1 gels are heat reversible. True or false?

Answer 29

False, irreversible

Question 30

Type 1 gels swell in water and dissolve. True or false?

Answer 30

false, do not dissolve due to stabilizing links

Question 31

Type 2 gels are heat reversible. What is meant by this?

Answer 31

On heating or cooling there is a transition from sol to gel and vice versa

Question 32

As temperature is increased, the solubility of type 2 gels increases. True or false?

Answer 32

False Decreases

Question 33

Why does the solubility of type 2 gels decrease as temperature is increased?

Answer 33

Because type 2 gels form micelles and upon warming, more and more micelles form. The micelles are formed so closely together that movement is prevented and a gel phase is formed

Question 34

A surfactant is an amphipathic molecule. What is meant by this?

Answer 34

It contains both hydrophilic groups and hydrophobic

Question 35

CMC decreases as length of hydrocarbon chain increases. True or false?

Answer 35

True

Question 36

How can the stability of an emulsion be increased?

Answer 36

Reduce globlet size, Decrease density difference, Increase viscosity of continuous phase

Question 37

What particle size is needed for good penetration into the airways?

Answer 37

1 - 5 micrometres

Question 38

Aerosol particles above 20 micrometres are deposited in the mouth and throat. True or false?

Answer 38

False More than 10

Question 39

What happens if the aerosol particles are less than 0.5 micrometres?

Answer 39

They may be exhaled

Question 40

What is a foam?

Answer 40

Dispersion of a gas in a liquid

Question 41

Surfactants are required for the formation of foams and emulsions. True or false?

Answer 41

True

Question 42

What are the two ways in which an aerosol can be prepared?

Answer 42

1. dispersion (a pressurized container, active ingredients contained within liquified propellant or additional solvent) 2. condensation (sample of vapour-saturated gas is subjected to rapid volume expansion, which lowers temp and causes supersaturation)

Question 43

Drugs for treatment of erectile dysfunction can be taken through nasal delivery formulations. True or false?

Answer 43

True

Question 44

Give 2 examples of drugs delivered via nasal drug delivery

Answer 44

Antihistamines and corticosteroids

Question 45

Give 2 examples of drugs delivered via pulmonary drug delivery

Answer 45

bronchodilators (local delivery) & sodium cromoglicate and Isoprenaline (systemic)

Question 46

How long is the nasal cavity?

Answer 46

12-14 cm long

Question 47

In the nasal cavity, cilia of the nasal vestibule filter out particles of which diameter?

Answer 47

Over 10 micrometres

Question 48

What is the main drug absorption site in the nasal cavity?

Answer 48

The epithelium of the nasal turbinates

Question 49

Particles of which diameter are deposited in the nasal cavity?

Answer 49

5-10 micrometres

Question 50

What is PecFent and what is it used for?

Answer 50

Nasal spray with API Fentanyl used for breakthrough pain in people already receiving opioids on a regular basis

Question 51

All drugs which are orally administered can be given rectally. True or false?

Answer 51

True but may not be as effective

Question 52

What are some disadvantages of rectal delivery systems?

Answer 52

Not favoured by patients Development of proctitis Slow and sometimes incomplete absorption of drug Problems with insertion Short shelf life