This Presentation is about Emulsions .An emulsion is a type of mixture formed by combining two immiscible liquids, where one liquid is dispersed in the other. These mixtures are stabilized through the use of emulsifiers, which are agents that prevent the separation of the two phases by reducing the surface tension between them.

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EMULSIONS

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EMULSIONS
Emulsion refers to a type of dispersed system consisting of two immiscible liquids,
typically oil and water, stabilized by the addition of an emulsifying agent.

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Emulsifying agent. .
 Emulsifying agents are the substance added to an emulsion to
prevent the coalescence of the globules of the dispersed phase.
 They are also known as emulgents of emulsifiers.
 They act by reducing the interfacial tension between the two
phases and forming a stable interfacial film.

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TYPES OF EMULSION
1. Water-in-oil (W/O)
2. Oil-in-water (O/W),
3. Complex emulsions such as water-in-oil-in-water (W/O/W).

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Difference between (W/O) and (O/W)
Emulsion
Water in Oil Emulsion
Oil is the dispersion medium and
water is the dispersed phase.
Greasy and not water washable
Used externally to prevent
evaporation of moisture from the
surface of skin e.g. Cold cream
Preferred for external use like
creams.
Oil in Water Emulsion
1. Water is the dispersion medium
and oil is the dispersed phase
2. Non greasy and easily
removeable from the skin
3. Used externally to provide cooling
effect e.g. vanishing cream
4. Preferred for internal use as bitter
taste of oils can be masked.

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Test for Identification of Type of
Emulsion
• Dilution test
• Conductivity test
• Dye solubility test
• Cobalt chloride test
• Florescence test

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Dilution test
This test can be conducted by adding water or oil to the
emulsion.

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Conductivity test
 Water is a good conductor of electricity whereas
 Oil is non-conductor. Therefore, continuous phase of water runs
electricity more than continuous phase of oil.

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Dye solubility test
In this test ,when emulsion is mixed with a water dye such as amaranth and
observed under microscope,
 If the continuous phase appears red then it means that the emulsion is O/W
type.
 If the discontinuous phase appears red and continuous phase is
colorless then it is W/O emulsion.

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Cobalt chloride test
Filter paper soaked in cobalt chloride solution and allowed to dry.
The filter paper will turns from blue to pink on exposure to O/W
emulsion.

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Methods for the preparation of
Emulsions

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Florescence test
 Oil gives florescence under UV light, while water doesn’t.
 Therefore, O/W emulsion shows spotty pattern when observed
under UV.
 While W/O emulsion shows continuous florescence.
W/O Emulsion O/W Emulsion