1. Emulsions

Question 1

What is Ansel’s definition of emulsions?

Answer 1

Emulsion is a dispersion in which the dispersed phase is composed of small liquids globules distributed throughout a vehicle in which it is immiscible.

Question 2

What is alternate definition of emulsions?

Answer 2

An emulsion is essentially a semi-solid preparation containing a mixture of oil and water that is rendered homogeneous by the addition of am emulsifying agent.

Question 3

What is internal phase?

Answer 3

Dispersed phase

Question 4

What is external phase?

Answer 4

Continuous phase

Question 5

What is an emulsifying agent?

Answer 5

It is another component required for preparing stable emulsions. Also known an emulgent or emulsifier.

Question 6

What are the types of emulsions?

Answer 6

1. O/W emulsions
2. W/O emulsions
3. Multiple emulsions

Question 7

What is O/W emulsion?

Answer 7

Emulsions with oleaginous internal phase and aqueous external phase (O/w)

Question 8

Give an example of O/W emulsion?

Answer 8

Milk, vanishing cream, mineral oil emulsion

Question 9

What is W/O emulsion?

Answer 9

Emulsions with an aqueous internal phase and oleaginous external phase (W/O)

Question 10

Give an example of W/O emulsion?

Answer 10

Cold cream

Question 11

What is multiple emulsion?

Answer 11

Emulsion in which an oil droplet enclosing a water molecule may be suspended in water to form water-in-oil-in-water emulsion or vice versa (W/O/W)

Question 12

Give advantages of emulsion?

Answer 12

1. Unpalatable oils can be administered in palatable forms
2. Aqueous phase is easily flavored
3. Taste of oil is masked
4. Absorption is improved
5. It is possible to add two immiscible liquids in emulsions form

Question 13

Give disadvantages of emulsions?

Answer 13

1. A measuring device is required for administration
2. Emulsions require shaking before use to ensure uniformity
3. Improper storage conditions can affect disperse system
4. Microbial contamination can lead to cracking
5. Emulsions are bulky and difficult to transport

Question 14

What are formulative additives of emulsions?

Answer 14

Antioxidants, preservatives and flavorants, colorants and perfumes

Question 15

What are antioxidants?

Answer 15

They are added to prevent oxidation of oil during its shelf life.

Question 16

Give examples of antioxidants.

Answer 16

ascorbic acid

Question 17

What are preservatives?

Answer 17

They are added for stability modification and increase in shelf life

Question 18

Give some examples of preservatives.

Answer 18

Benzoin acid, chloroform, chloroform water, methyl paraben, benzyl alcohol etc.

Question 19

Why are flavorants, colorants and perfumes used?

Answer 19

To increase appeal

Question 20

What is emulsifier?

Answer 20

Emulsifier is any material which promotes emulsification and maintains the stability for intended shelf life of product.

Question 21

What is the criteria for emulsifier?

Answer 21

1. It should be stable
2. It should be compatible with other ingredients
3. It should be non toxic
4. It should possess little or no color, odor or taste
5. It should not intervene with safety or efficacy of formulation

Question 22

What is HLB value?

Answer 22

Hydrophilic-lipophilic balance is the number indicating the polarity of substance. Although HLB values are assigned till 40, usual range is 1-20

Question 23

What does the value 3-6 indicate?

Answer 23

Greatly lipophilic, produces W/O emulsions

Question 24

What does the value 8-18 indicate?

Answer 24

It shows hydrophilic, produced O/W emulsions

Question 25

HLB value of acacia

Answer 25

8

Question 26

sorbitan laurate

Answer 26

8.6

Question 27

sorbitan stearate

Answer 27

4.7

Question 28

Polysorbate 20

Answer 28

16.7

Question 29

Polysorbate 80

Answer 29

15

Question 30

Sodium Lauryl stearate

Answer 30

40

Question 31

sodium oleate

Answer 31

18

Question 32

Tragacanth

Answer 32

13.2

Question 33

Triethanolamine oleate

Answer 33

12

Question 34

What are the methods of preparation of emulsion?

Answer 34

1. Continental/Dry gum method 2. English/Wet gum method 3. Forbes or Bottle method 4. Auxilliary method

Question 35

What is the continental method of emulsion preparation?

Answer 35

Emulsifying agent is mixed with oil before addition of water. It is also called 4:2:1 method (4 parts oil, 2 parts 1, 1 part emulsifying agent)

Question 36

Describe the method of continental emulsion method.

Answer 36

1. Emulsifying agent is triturated with oil until thoroughly mixed 2. Two parts of water added at once and triturated 3. Primary emulsions is produced when crackling sound formed 4. Other ingredients are added

Question 37

What is the formula of mineral oil emulsion?

Answer 37

Mineral oil - 500 mL Acacia - 125 g syrup - 100mL Vanillin - 40 mg Alcohol - 60 mL Water to 100 mL Prepared by dry gum method

Question 38

What is the use of mineral oil?

Answer 38

As lubricating cathartic with usual dose 30 mL

Question 39

What is the English/wet gum method?

Answer 39

Water and emulsifier are mixed and oil is added later. 1. Mucilage of gum is prepared by dissolving twice weight of water in mortar. 2. Oil is added in portions and triturated 3. Mixed for several minutes to ensure uniformity. 4. Other formulative ingredients are added.

Question 40

What is the formula for liquid paraffin emulsion?

Answer 40

Liquid paraffin - 30mL Acacia - 7.5 g Water to 1000mL Prepared by wet gum method

Question 41

What is the use of liquid paraffin emulsion?

Answer 41

It is used as a laxative for constipation.

Question 42

What is the forbes or bottle method?

Answer 42

It is used for the extemporaneous preparation of emulsions. 1. Acacia is placed in capped bottle. 2. Two parts oil is added. 3. Mixture is thoroughly shaken. 4. Volume of water equal to oil is added and shaken. 5. Mixture is shaken. 6. Remaining water is added and shaken.

Question 43

What is auxilliary method?

Answer 43

Hand homogenizer is used. 1. Primary emulsion is produced by using either dry gum or wet gum method. 2. Emulsion is forced through a small orifice 3. Globule size reduced upto 5 micrometer 4. Quality of emulsion increased.

Question 44

What is an emulgel?

Answer 44

An emugel is basically a gellified emulsion, prepared by mixing an o/w or w/o emulsion with gelling agent. Different anti-fungals, anti-inflammatory and other drugs are prepared in the form of emulgels.

Question 45

What are the advantages of emulgels?

Answer 45

1. Dual control of drug release, emulsion and gel 2. Enhanced stability 3. Well suited for hydrophobic drugs

Question 46

Name some emulsions available in the market?

Answer 46

1. Rozex (Metronidazole) - topical antibacterial 2. Diprivan (propofol) - IV sedative 3. Cremaffin (liquid paraffin) - oral laxative 4. Voltral emulgel (diclofenac diethylamine) - topical anti-inflammatory

Question 47

Give information about the packaging of emulsions.

Answer 47

Plain amber colored bottle is used for oral emulsions with CRC's Amber colored fluted bottles for topical emulsions

Question 48

Storage of emulsions

Answer 48

Store at cool and dry place. Use in maximum 1 month after opening.

Question 49

Advisory label for emulsions.

Answer 49

"Shake well before use" for both oral and topical emulsions "For external use only" for external emulsions