This document defines and compares different types of emulsions including multiple emulsions, microemulsions, nanoemulsions, and nanosuspensions. It explains that emulsions are mixtures of two immiscible liquids stabilized by an emulsifying agent, while microemulsions are more thermodynamically stable with smaller droplet sizes. Nanoemulsions have droplets between 5-200nm and are kinetically stable. Nanosuspensions are solid drug particles less than 1um suspended in water stabilized by surfactants to improve dissolution and bioavailability. The document provides details on identification tests, preparation methods, advantages and disadvantages of these various emulsion systems.

1. BRIEF INTRODUCTION TO
MULTIPLE EMULSION,
MICROEMULSION,
NANOEMULSION &
NANOSUSPENSION
Presented by- Md . Shariq Ansari
B.Pharm 5th sem
Under the guidance: Mr. Dilip Kr. Patel

2. CONTENT
• Defination
• Emulsion
• Types Of Emulsions
• Identification test for emulsion
• Emulsifying agent
• Method of preparation of emulsion
• Microemulsion
• Nanoemulsion
• Nanosuspension

3. DEFINATION
• An Emulsion is a mixture of two or more liquids that
are normally Immiscible.
OR
• Emulsion, is a mixture of two or more liquids in which
one is present as droplets, of microscopic or
ultramicroscopic size, distributed throughout the other.
OilOil
WaterWater
Oil
Water
Agitation
Separate rapidly into two
clear defined layers
OilOil
WaterWater
Oil
Water
Agitation
Separate rapidly into two
clear defined layers

4.  Emulsion
 Microemulsion
 Nanoemulsion
 Thermodynamically unstable
 Opaque
 High energy required to form
 Thermodynamically stable
 Clear
 It forms spontaneously
 Thermodynamically or kinetically stable
 Clear
 High shear application to form
Int. J. Nanomed. 2014,9,pp 1-8

6. Internal Phase or External Phase in
Emulsions:
 The dispersed liquid is known as the Internal or
Discontinuous phase.
 whereas the dispersion medium is known as
the External or Continuous phase.

7. Based on size of liquid droplets:
 0.2 – 50 mm Macroemulsions
 0.01 – 0.2 mm Microemulsions

9. IDENTIFICATION TEST FOR
EMULSIONS:
By using Naked eye, it is very difficult to
differentiate between o/w or w/o emulsions. Thus, the
following methods have been used to identify the
type of emulsions.
1) Dye Test
2) Dilution Test
3) Electrical conductivity Test
4) Fluorescence Test.

10. EMULSIFYING AGENT:
• Emulsions are stabilized by adding an emulsifying agent.
• These agents have both a hydrophilic and a Lipophilic
part in their chemical structure.
• All emulsifying agents get adsorbed onto the Oil : water
interface to provide a protective barrier around the
dispersed droplets.
• In addition to this protective barrier, emulsifiers stabilize
the emulsion by reducing the interfacial tension of the
system.
• E.g. agar, albumin, cholic acid, glycerol, gums, soaps,
casein, ox bile extract.

11. METHODS OF PREPARATION
OF EMULSIONS:
• Commercially, emulsions are prepared in large
volume mixing tanks and refined and stabilized
by passage through a colloid mill or homogenizer.
Extemporaneous production is more concerned
with small scale methods.
1) Dry Gum Methods
2) Wet Gum Methods
3) Bottle Method

15. MICROEMULSION
• Micro Emulsions are dispersions of oil and water made
with surfactant, co-surfactant molecules. In many respects,
they are small-scale versions of emulsions. However, the
droplet sizes are very small, typically 100 A, about 100
times smaller than typical emulsion droplet sizes.
W/O O/W

16. OR
• “Microemulsions are liquid dispersions of water and oil that
are made homogenous, transparent (or translucent) and
thermodynamically stable by the addition of relatively large
amounts of a surfactant and a co-surfactant and having
diameter of the droplets in the range of 100 – 1000 A (10 –
100 nm).
(Figure :
Microemulsion
Structure)

17. Advantages of Microemulsions:
.These are thermodynamically stable .
. Require minimum energy for formation.
. Easy of manufacturing .
. Improved drug solubilization and bioavailability.
. Wide applications in colloidal drug delivery systems.
. The formation of microemulsion is reversible.
. Improve the efficacy of a drug & Minimum side effects.
Disadvantages of Microemulsions:
•Use of a large concentration of surfactant and co-surfactants.
• Limited solubilizing capacity for high-melting substances.
• The surfactant must be nontoxic for using pharmaceutical
applications.
• Microemulsion stability is influenced by environmental parameters
such as temperature and pH.

18. NANOEMULSIONS
• Dispersion of two immiscible liquids stabilized
by a surfactant
• Thermodynamically and kinetically stable
• Droplets from 5 to 200 nm

19. Nanoemulsions - Applications
 Agriculture
 Cleaning products
 Cosmetic
 Pharmaceutic
 Biomedical

20. Nanoemulsions - Drug Delivery
Advantages
 Increase drug loading
 Enhance drug solubility
 Bioavailability
 Controlled drug delivery
 Protection of drug
 Disadvantages
 Expensive process
 Stability
 Solubility
 Lack of understanding of interfacial chemistry
J. Phys. Chem. C 2008, 112 (33), 12669-12676.

21. NANOSUSPENSION
Definition:
“A very finely dispersed solid drug particles in an
aqueous vehicle in which diameter of suspended particle is
less than 1 µm in size, stabilized by surfactants, for either
oral and topical use or parentral and pulmonary
administration, with reduced particle size, leading to an
increased dissolution rate and therefore improved
bioavailability”.
 Average particle size ranges from 200-600 nm.
 In nanosuspension technology, the drug is
maintained in the required crystalline state with reduced
particle size, Improved bioavailability leading to an
increased dissolution rate.

22. ADVANTAGES
 Can be applied for the poorly water soluble
drugs.
 Rapid dissolution and tissue targeting can be
achieved by IV route of administration.
 Oral administration of nanosuspensions provide
rapid and improved bioavailability.
 Long-term physical stability due to the
presence of stabilizers.
 Nanosuspensions can be incorporated in
tablets, pellets, hydrogels.
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23. DISADVANTAGES
Physical stability, sedimentation and
compaction can causes problems.
It is bulky sufficient care must be taken during
handling and transport.
Uniform and accurate dose cannot be
achieved unless suspension .
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