Emulsions

Question 1

Four kinds of emulsifying and emulsion stabilizing agents

Answer 1

Hydrophilic colloids
Protein substances
High molecular weight alcohols
Wetting agents or surface acting agents

Question 2

Acacia & Tragacanth

Answer 2

Hydrophilic Coloid

Question 3

Chrondus and Pectin

Answer 3

Hydrophilic Colloid

Question 4

Do hydrophilic colloids reduce interfacial tension?

Answer 4

no, they do little to reduce interfacial tension.

Question 5

What emulsions should hydrophilic colloids be used for?

Answer 5

O/W

Question 6

Do hydrophilic colloids act as film formers?

Answer 6

Yes, they do.

Question 7

Are hydrophilic colloids used in commercial preparations?

Answer 7

Not commonly

Question 8

Gelatin

Answer 8

Protein substance

Question 9

egg yolk

Answer 9

protein substance

Question 10

Casein

Answer 10

protein substance

Question 11

What emulsion types are protein substances used for?

Answer 11

O/W emulsions

Question 12

Gelatin special property (in making fluid emulsions)

Answer 12

Gelatin produces very fluid emulsions that become more fluid upon standing

Question 13

Are protein substances commonly used in commercial drug products?

Answer 13

No

Question 14

Which stabilizing agent is commonly used to make IV Fat emulsions?

Answer 14

Protein Substances

Question 15

Name the common Molecular Weight Alcohols

Answer 15

Stearyl Alcohol, Cetyl alcohol, glyceryl monosterate, cholesterol

Question 16

What are high molecular weight alcohols used for?

Answer 16

Thickening and stabalziign agents

Question 17

What emulsion type are high molecular weight alcohols used for?

Answer 17

O/W Emuslions

Question 18

Common Wetting Agents

Answer 18

Span 80, Tween 60, triethanolamine oleate, (Tween 60), sodium lauryl sulfate (SLS)

Question 19

What is the charge on wetting agents? (ionic, etc?)

Answer 19

Can be anionic, cationic, or nonionic

Question 20

Which do wetting agents contain: lipophilic or hydrophilic groups?

Answer 20

Contain BOTH lipophillic and hydrophilic groups

Question 21

What emulsion types are wetting agents used in? Explain why:

Answer 21

O/W and W/O.

Contain BOTH lipophillic and hydrophilic groups

Question 22

which is the most commonly used surfactant category?

Answer 22

Wetting agents

Question 23

Which HLB values create W/O Emulsions?

Answer 23

3-6

Question 24

Which HLB values create O/W Emulsions

Answer 24

8-18

Question 25

High HLB values means what (lipophillic/hydrophillic?

Answer 25

Hydrophilic and polar

Question 26

Low HLB value means what? (hydrophilic or lipophilic?)

Answer 26

Lipophillic and less polar

Question 27

in terms of the Gibbs free energy formula, what properties does a Good emulsion have?

Delta G = Delta A * Y

Answer 27

A low delta G is thermodynamically the most stable

Question 28

If an emulsion has increased in particle size, what should be done to decrease Delta G

Answer 28

Reducing Y which is the interfacial tension. Reducing Interfacial tension will increase repulsion of the particles which can help with stability and avoid coalescing

Question 29

In terms of Gibbs Free Energy, what qualities does a bad emulsion have

Answer 29

High A (High surface area) and a High Y

or High G and a High Y which will mean the droplets are coalescing which is not good for an emulsion

Question 30

When an emulsion cracks, what is this caused by? In terms of Gibbs Free Energy

Answer 30

When Delta G is high, the emulsion will try to reduce A, which decreases the surface area, and the particles ultimately coalesce. In doing this, the emulsion cracks.