37 Questions
What type of emulsion is typically used for orally administered drugs?
o/w emulsion
For patients unable to ingest food, what type of emulsion is used for the administration of nutritive oil and oil soluble vitamins?
o/w emulsion
Intravenous emulsions must be:
o/w
What determines whether an emulsion for topical use is o/w or w/o?
The nature of therapeutic agents and desired effects
What is the continental or dry gum method also known as?
4:2:1 method
What is the purpose of using a mortar with a rough inner surface in the continental method?
To ensure proper reduction of the internal phase
How much water is added for 40 mL of oil in the continental method?
20 mL
Why is a glass mortar not suitable for the continental method?
It does not produce proper reduction of the internal phase
What is the term used for the preparation of the globules in the emulsion?
Creaming
Which factors are related to the rate of separation of the dispersed phase in an emulsion, according to the Stokes equation?
Particle size, density difference, and viscosity
In what type of emulsions does upward creaming take place?
Unstable o/w type emulsions
What are the strategies for enhancing stability of emulsions?
Minimizing particle size, minimizing density difference, and maximizing external phase viscosity
What is the Gibbs free energy equation for an emulsion?
$ΔG = ΔA γ$
What must be done to achieve stable emulsions for consistent and uniform dosing?
Decrease interfacial tension (γ) to decrease self-attraction of dispersed phase particles
What force resists the formation of smaller droplets when two immiscible liquids come into contact?
Surface tension
What problem may be caused by storage conditions affecting the disperse system of emulsions?
Creaming or cracking
What is the indication for Simethicone Emulsion?
Defoaming agent for relief of gastrointestinal gas symptoms
Which type of emulsion are many hand and body lotions for dry skin?
Oleaginous/water-in-oil (o/w)
What is the key characteristic of liniments?
Rubbed on the skin as alcoholic or oleaginous solutions or emulsions
What is the primary purpose of shampoos as mentioned in the text?
Hair and scalp cleansing
What factors are related to the rate of creaming in emulsions?
Particle size, density difference, viscosity of the external phase
In which type of emulsion does downward creaming take place?
Stable w/o emulsions
What is the term for the process that can restore creamed emulsion to its original state?
Reversion
What strategies are recommended for enhancing the stability of emulsions?
Reducing particle size, minimizing density difference, increasing viscosity of the external phase
What is the primary function of emulsifying agents in reducing interfacial tension between immiscible liquids?
To decrease the attraction between the two liquids' molecules
According to the Oriented-Wedge Theory, how do emulsifying agents form layers around the droplets of the internal phase?
By forming monomolecular layers around the droplets
What determines whether an emulsion is o/w or w/o, based on the characteristics of emulsifying agents?
The emulsifying agents' hydrophilic or hydrophobic character
Why do emulsifying agents with a more hydrophobic character favor w/o emulsions?
Because they have a stronger attraction to their own molecules
What is the term for the process of an exchange between the disperse phase and the medium in an emulsion?
Inversion
Why is breaking of an emulsion considered irreversible?
The protective sheath about the globules of the internal phase no longer exists
What environmental factors must be considered for protecting emulsions?
Light and temperature
Why does freezing and thawing coarsen an emulsion?
It disrupts the protective sheath around the globules
In the large-scale preparation of emulsions, what equipment may be employed to refine the emulsion further?
High-pressure homogenizers
Which process refers to the aggregation or joining of droplets together (without any change in primary droplet size) to form large clumps or floccules in an emulsion?
Flocculation
Which instability of emulsions is characterized by the aggregates of globules of the internal phase having a greater tendency to rise to the top or fall to the bottom of the emulsion?
Creaming or sedimentation
What is the term for the process of restoring creamed emulsion to its original state?
Re-emulsification
What type of emulsion is typically used for hand and body lotions for dry skin?
O/W emulsion
Test your understanding of the continental or dry gum method for preparing emulsions, as discussed in Chapter 14 of Disperse Systems. Explore the 4:2:1 ratio and the process of triturating the emulsifying agent with oil before adding water.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
