Disperse Systems: Emulsions and Emulsifying Agents

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What is the fraction of Tween 80 used in the emulsion formulation?

0.25

0.75

0.42

0.58 (correct)

What is the fraction of Span 80 used in the emulsion formulation?

0.58

0.25

0.75

0.42 (correct)

How much Sorbitan monooleate is required for the emulsion formulation?

50 g

2.1 g (correct)

2.9 g

5 g

How much Polyoxyethylene 20 sorbitan monoleate is required for the emulsion formulation?

2.9 g Signup and view all the answers

What is the purpose of heating the oil-soluble sorbitan monooleate to 75°?

To dissolve it in the oil Signup and view all the answers

Why is the water-soluble polyoxyethylene 20 sorbitan monooleate added to the aqueous phase at 70°?

To prevent it from solidifying Signup and view all the answers

What does the formulator mean by not being restricted to using only the mentioned emulsifying agents?

Other combinations of emulsifying agents can also achieve an HLB of 10.5 Signup and view all the answers

Why are various methods employed for emulsion preparation?

To adapt to the nature of components and desired emulsion characteristics Signup and view all the answers

What is the primary indication for Castor Oil Emulsion?

Laxative for constipation Signup and view all the answers

Which type of emulsion are many hand and body lotions for dry skin?

o/w emulsions Signup and view all the answers

What are liniments intended for?

Rubbing on the skin Signup and view all the answers

What does Simethicone Emulsion act as?

Defoaming agent for relief of gastrointestinal gas symptoms Signup and view all the answers

What is the emulsifying agent formed from the combination of olive oil and calcium?

Oleic acid Signup and view all the answers

What equipment is used on a larger scale for emulsion formation?

High-speed impellers Signup and view all the answers

Which process refers to the aggregation or joining of droplets without any change in primary droplet size?

Flocculation Signup and view all the answers

What contributes to the tendency of aggregates of globules to rise to the top or fall to the bottom of an emulsion?

Phase separation Signup and view all the answers

What is the primary purpose of pharmaceutical emulsions?

To enhance the stability of drugs Signup and view all the answers

Which factor plays a significant role in affecting the stability of emulsions?

Particle size of the dispersed phase Signup and view all the answers

What distinguishes microemulsions from macroemulsions?

Microemulsions are optically transparent Signup and view all the answers

What is the primary function of emulsifying agents in pharmaceutical emulsions?

To reduce the interfacial tension between oil and water phases Signup and view all the answers

What is the ratio of surfactant A to surfactant B to achieve a total HLB value of 9.0?

1:2 Signup and view all the answers

How is the total HLB value of a mixture of surfactants calculated?

Adding the HLB values of the surfactants Signup and view all the answers

Why may combining two or more emulsifiers be necessary to achieve the required HLB value?

To achieve the desired stability of the emulsion Signup and view all the answers

What is assumed to be an algebraic summation of the HLB for a mixture of surfactants?

$HLB_{total} = HLBA ( X) + HLBB (1-X)$ Signup and view all the answers

What is the crucial step to consider prior to emulsion preparation?

Dissolving water-soluble ingredients in the aqueous phase Signup and view all the answers

Why is it important to warm the aqueous phase 2-3°C above the oil phase?

To prevent local crystallization of waxes Signup and view all the answers

Why should alcohol or solutions containing alcohol not be added directly to the primary emulsion?

To prevent precipitation of gums such as acacia Signup and view all the answers

When should substances that might interfere with the stability of the emulsion be added?

After all diluents are added Signup and view all the answers

Why is the Forbes bottle method not suitable for viscous oils?

Viscous oils cannot be thoroughly agitated in the bottle when mixed with the emulsifying agent. Signup and view all the answers

What is the purpose of passing an emulsion through a hand homogenizer?

To reduce the globules of the internal phase to a very small size. Signup and view all the answers

What type of soaps are developed by the In Situ Soap Method?

Calcium soaps and soft soaps. Signup and view all the answers

Why are viscous oils not suitable for the Forbes bottle method?

They cannot be thoroughly agitated in the bottle when mixed with the emulsifying agent. Signup and view all the answers

In emulsion terminology, what is the dispersed phase also known as?

Internal phase Signup and view all the answers

What is the primary role of an emulsifying agent in preparing a stable emulsion?

To prevent the aggregation of droplets Signup and view all the answers

Which type of emulsion can be diluted or extended with water or an aqueous preparation?

Oil-in-Water (o/w) Emulsions Signup and view all the answers

What distinguishes multiple emulsions from macroemulsions?

The presence of more than two immiscible liquids Signup and view all the answers

Why is the dry gum method generally employed when the intended dispersed phase is a mixture of fixed oil and volatile oil?

To increase the emulsion's stability Signup and view all the answers

What is the primary reason for passing an emulsion through a hand homogenizer?

To reduce the particle size of very thick emulsions Signup and view all the answers

What are the two types of soaps developed by the In Situ Soap Method?

Calcium soaps and magnesium soaps Signup and view all the answers

Why is the Forbes bottle method not suited for viscous oils?

Because it cannot thoroughly agitate viscous oils mixed with the emulsifying agent in the bottle Signup and view all the answers

What is the fraction of Polyoxyethylene 20 sorbitan monoleate required for the emulsion formulation?

3.8 g Signup and view all the answers

What is the total HLB value of the mixture of Tween 80 and Span 80 used to produce a physically stable liquid paraffin emulsion?

10.5 Signup and view all the answers

Why might combining two or more emulsifiers be necessary to achieve the required HLB value?

To modify the hydrophilic-lipophilic balance Signup and view all the answers

What contributes to the tendency of aggregates of globules to rise to the top or fall to the bottom of an emulsion?

Density difference between the dispersed phase and dispersion medium Signup and view all the answers

Why is it important for o/w emulsions to be easily removed from the skin?

To enhance percutaneous absorption Signup and view all the answers

What is a crucial step required to prevent the separation of phases in pharmaceutical emulsions?

Careful formulation to prevent the separation of phases Signup and view all the answers

Which characteristic makes w/o emulsions more suitable for dry skin?

Resisting drying and removal by contact with water Signup and view all the answers

What is a disadvantage of pharmaceutical emulsions?

Require careful formulation to prevent phase separation Signup and view all the answers

Disperse Systems: Emulsions and Emulsifying Agents

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Questions and Answers

What is the fraction of Tween 80 used in the emulsion formulation?

What is the fraction of Span 80 used in the emulsion formulation?

How much Sorbitan monooleate is required for the emulsion formulation?

How much Polyoxyethylene 20 sorbitan monoleate is required for the emulsion formulation?

What is the purpose of heating the oil-soluble sorbitan monooleate to 75°?

Why is the water-soluble polyoxyethylene 20 sorbitan monooleate added to the aqueous phase at 70°?

What does the formulator mean by not being restricted to using only the mentioned emulsifying agents?

Why are various methods employed for emulsion preparation?

What is the primary indication for Castor Oil Emulsion?

Which type of emulsion are many hand and body lotions for dry skin?

What are liniments intended for?

What does Simethicone Emulsion act as?

What is the emulsifying agent formed from the combination of olive oil and calcium?

What equipment is used on a larger scale for emulsion formation?

Which process refers to the aggregation or joining of droplets without any change in primary droplet size?

What contributes to the tendency of aggregates of globules to rise to the top or fall to the bottom of an emulsion?

What is the primary purpose of pharmaceutical emulsions?

Which factor plays a significant role in affecting the stability of emulsions?

What distinguishes microemulsions from macroemulsions?

What is the primary function of emulsifying agents in pharmaceutical emulsions?

What is the ratio of surfactant A to surfactant B to achieve a total HLB value of 9.0?

How is the total HLB value of a mixture of surfactants calculated?

Why may combining two or more emulsifiers be necessary to achieve the required HLB value?

What is assumed to be an algebraic summation of the HLB for a mixture of surfactants?

What is the crucial step to consider prior to emulsion preparation?

Why is it important to warm the aqueous phase 2-3°C above the oil phase?

Why should alcohol or solutions containing alcohol not be added directly to the primary emulsion?

When should substances that might interfere with the stability of the emulsion be added?

Why is the Forbes bottle method not suitable for viscous oils?

What is the purpose of passing an emulsion through a hand homogenizer?

What type of soaps are developed by the In Situ Soap Method?

Why are viscous oils not suitable for the Forbes bottle method?

In emulsion terminology, what is the dispersed phase also known as?

What is the primary role of an emulsifying agent in preparing a stable emulsion?

Which type of emulsion can be diluted or extended with water or an aqueous preparation?

What distinguishes multiple emulsions from macroemulsions?

Why is the dry gum method generally employed when the intended dispersed phase is a mixture of fixed oil and volatile oil?

What is the primary reason for passing an emulsion through a hand homogenizer?

What are the two types of soaps developed by the In Situ Soap Method?

Why is the Forbes bottle method not suited for viscous oils?

What is the fraction of Polyoxyethylene 20 sorbitan monoleate required for the emulsion formulation?

What is the total HLB value of the mixture of Tween 80 and Span 80 used to produce a physically stable liquid paraffin emulsion?

Why might combining two or more emulsifiers be necessary to achieve the required HLB value?

What contributes to the tendency of aggregates of globules to rise to the top or fall to the bottom of an emulsion?

Why is it important for o/w emulsions to be easily removed from the skin?

What is a crucial step required to prevent the separation of phases in pharmaceutical emulsions?

Which characteristic makes w/o emulsions more suitable for dry skin?

What is a disadvantage of pharmaceutical emulsions?

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