2. Contents
Definition
Types of Emulsion
Pharmaceutical Application
Emulsifying Agents
Theory of Emulsification
Methods of Preparation
Equipment Used in Production Process
Problem Encountered
Packaging, Labeling & storage
Conclusion
References
3. EMULSION
An emulsion is a thermodynamically unstable
system consisting of at least two immiscible
liquid phases one of which is dispersed as
globules in the other liquid phase stabilized by a
third substance called emulsifying agent.
5. EMULSION
A B C D
A.: Two immiscible liquids not emulsified
B. An emulsion of phase B dispersed in Phase A
C. Unstable emulsion slowly separates.
D. The emulsifying agent stabilizes the emulsion.
Phase A
Phase B
8. MULTIPLE EMULSION
• Multiple emulsions are complex polydispersed
systems where both oil in water and water in
oil emulsion exists simultaneously which are
stabilized by lipophillic and hydrophilic
surfactants respectively
9. MICRO EMULSION
Micro emulsions are clear, thermodynamically
stable, isotropic liquid mixtures of oil, water and
surfactant, frequently in combination with a
cosurfactant.
The aqueous phase may contain salt(s) and/or
other ingredients, and the "oil" may actually be
a complex mixture of different hydrocarbons.
10. Microemulsion Emulsion
Transparent Yes No
Size 10-120 nm 0.1 – 10 µ
Formation Spontaneous Require
shaking
Type o/w, w/o. cylinder o/w, w/o,
w/o/w, o/w/o
Stability Thermodynamically
stable
Thermodynam
ically unstable
Viscosity Can accommodate 20 to
40% without increase in
viscosity
More viscous
11. Pharmaceutical application
of Micro Emulsion
• Increase bioavailability of drugs
poorly soluble in water.
• Topical drug delivery systems
• Rapid action
• Low dose required
15. THEORY OF
EMULSIFICATION
Droplets can be stabilized by three methods
i. By reducing interfacial tension
ii. By preventing the coalescence of
droplets.
a. By formation of rigid interfacial film
b. By forming electrical double layer.
16. Theory of emulsification:
Reduction of interfacial tension
•
Phase A
Phase B
Change from A to B
increases surface area of
phase A, hence the Due to
increased surface energy, the
system is thermodynamically
unstable.
A
B
Emulsifying agents are needed to decrease the
interfacial tension and to stabilize the emulsion.
19. Theory of emulsification –
Formation of electrical double layer
- -
-
-
-
-
+
+
+
+
+
-
-
-
-
-
-
-
+
+ +
+
Electrical double layer at oil-water interface
Emulsion made with
sodium soap.
Oil
Water
20. Method of Preparation
Wet gum method
Also known as “English Method”
4:2:1 of Oil : Water : Gum
Formation of primary gum at the nucleus of the
emulsion
21. Dry gum method
Also known as “Continental Method”
4:2:1 of Oil : Water : Gum
Formation of primary gum at the nucleus
of the emulsion
26. For drawing the material to be mixed from above.
Generates axial flow in the vessel.
Turbine stirrer
27. Propeller stirrers
• Standard stirring element.
For drawing the material
to be mixed from the top
to the bottom.
• Generates axial flow in the
vessel.
• Used at medium to high
speeds.
.
30. Emulsion stability
( Instability) - Types
• Physical instability
• i. Flocculation
• Ii. Creaming or sedimentation
• iii. Aggregation or coalescence
• Iv. Phase inversion
31. Flocculation:
Two or more droplet stick together to form an
aggregate
Creaming:
The process is reversible and gentle shaking
redistributes the droplets throughout the continuous
phase.
Aggregation:
Two or more droplet stick together to form a single
large droplate
Phase inversion:
Here o/w emulsion change in w/o or vice-versa
32. Packaging, Labeling And Storage Of Emulsions
Emulsions meant for oral use are usually packed in well
filled bottles having an air tight closure.
Light sensitive products are packed in
amber coloured bottles.
Emulsions should be stored in a cool place but
refrigeration should be avoided as this low temperature
can adversely effect the stability of preparation.
34. CONCLUSION
• Emulsion are drug of choice for conditions such
as, drug having unpleasant taste and odour,
protection from environmental condition, to
increase bioavailability. But there are also
certain things need to improve like
thermodynamically instability of emulsion. But
in recent days advances in emulsion technology
like micro emulsion and nano emulsion came,
which increase the stability.
35. References
• Herbert A. Lieberman, Leon Lachman. The Theory and Practice
of Industrial Pharmacy, published byCBS Publishers &
Distributors Pvt. Ltd., New Delhi (2008),7th edition, ISBN-
10: 8123922892, page 502-532.
• Ramington. The Science and Practice of Pharmacy,21st
edition,Vol-I,published by Lippincott Williams and
Willinkin,2011, ISBN-10: 0781746736,page745-745.
• Sreenivas SA, Dandagi PM, Gadad AP, Godbloe AM, Hiremath
SP, Mastiholimath VS. Disperse system: Current advances– A
review. Indian J Pharm Educ Res, 2005; 39(4):177-181.