18 Questions
What type of disperse system is a pharmaceutical emulsion?
Heterogeneous system
Which phase is finely divided and distributed throughout the other phase in a pharmaceutical emulsion?
Dispersed phase
Which type of emulsion has an oily continuous phase?
Water in oil (w/o)
What is the role of an emulsifying agent in a pharmaceutical emulsion?
To stabilize the dispersed phase in the continuous phase
What type of dosage forms are almost o/w type emulsions convenient for administering?
Oily solution drugs
Which hydrophilic colloid is commonly used in extemporaneously prepared internal emulsions?
Acacia gum
What is the compounding technique called where acacia is triturated with water before adding oil in small amounts?
Wet gum method
What is the primary color of print used for labeling in the described pharmaceutical preparation?
Black
Which mechanism describes the phenomenon where emulsion droplets merge to form larger droplets?
Coalescence
What could cause the breaking of an emulsion due to droplets merging to form even larger droplets?
Freezing
Which technique involves adding volatile oils and low-viscosity oils in a bottle method?
Forbes bottle method
What would be an appropriate auxiliary label for a pharmaceutical emulsion to prevent excessive usage?
"Keep out of reach of children"
What is the main role of liquid paraffin in the pharmaceutical preparation described in the text?
Active ingredient
In the compounding method described, what is the purpose of using the dry gum method?
To prepare a stable emulsion
Which component is responsible for giving the emulsion its sweet taste?
Sodium saccharine
What is the primary purpose of adding benzoic acid and chloroform to the preparation?
Preservation
Why is it essential not to over mix when adding acacia to the paraffin oil?
To maintain stability of the emulsion
What could be the consequence of not using a dry mortar and pestle during the compounding process?
Formation of lumps in the preparation
Study Notes
Pharmaceutical Emulsions
- A pharmaceutical emulsion is a type of disperse system consisting of two immiscible liquids, where one liquid (the dispersed phase) is finely divided and distributed throughout the other (the continuous phase).
- Emulsions can be prepared for oral, external, parenteral, and ophthalmic use as liquids or semisolids.
Types of Emulsions
- Oil in water (o/w) emulsions: the continuous phase is aqueous.
- Water in oil (w/o) emulsions: the continuous phase is oily.
Factors Affecting Emulsion Type
- Relative proportions of the two present phases.
- Type of selected emulsifying agent.
Oral Dosage Forms
- Emulsions as oral dosage forms are almost o/w type.
- Convenient means of administering unpleasant oily solution drugs.
Preparing Acacia Emulsions
- Use acacia gum (hydrophilic colloid) as an emulsifying agent.
- Make a thick primary emulsion first using pestle and mortar.
- Wet gum method (English method) and Forbes bottle method are two compounding techniques.
Labeling and Storage
- Labels: "Keep out of reach of children", "For oral use", "Shake well before use", & "Avoid excessive use".
- Shelf life: one month.
- Storage conditions: "store in cool and dry place, avoid freezing".
Instability Mechanisms
- Creaming: emulsion separates due to density difference, where oil droplets rise to the surface.
- Flocculation: droplets come together to form larger droplets.
- Coalescence: droplets merge to form even larger droplets.
- Freezing can cause coalescence, leading to breaking of the emulsion.
- Heating can lead to creaming, which is reversible by shaking.
Active Pharmaceutical Ingredients and Additives
- Liquid paraffin: active pharmaceutical ingredient, used as a laxative.
- Sodium saccharine: non-caloric sweetening agent.
- Vanillin: flavoring agent.
- Chloroform (single strength) and benzoic acid (aqueous solution): preservatives.
- Acacia: emulsifying agent.
Compounding Method
- Dry gum method (continental method): measure required volume of paraffin oil, weigh acacia, and mix lightly using a dry pestle to disperse lumps.
- Gradually dilute the primary emulsion with small volumes of water, ensuring complete mixing between additions.
This quiz explores the characteristics and preparation of pharmaceutical emulsions used for various routes of administration such as oral, external, parenteral, and ophthalmic. Learn about the components of a pharmaceutical emulsion and its types.
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