Miroemulsion

2. SEMINAR ON
MICROEMULSION
BY
MR.VISHAL R. MOHITE
UNDER GUIDANCE OF
PROF. K. K. MALI
M.PHARM(BIOPHARMACEUTICS)

3. CONTENT
 INTRODUCTIONTO EMULSION
 TYPES OF EMULSION
 DIFFERENCE BETWEEN EMULSION AND
MICROEMULSION
 INTRODUCTION TO MICROEMULSION
 ADVANTAGES
 DISADVANTAGES
 TYPES OF MICROEMULSION SYSTEMS
 COMPONENTSOF MICROEMULSION

4. CONTENT
 STRUCTUREOF MICROEMULSION
 CONSTRUCTIONOF PSEUDOTERNARY
PHASE DIAGRAMMETHODOF
PREPARATION
 METHOD OF PREPARATION
 APPLICATION OF MICROEMULSION IN
DELIVERY OF DRUG

5. INTRODUCTION TO EMULSION
 DEFINATION
Emulsion can be defined as thermodynamically
unstable system consisting of at least two
immiscible liquid phases, one of which is dispersed
as globule in the other liquid phase
OR
Emulsion can be defined as dispersion two
immiscible phases in which one is dispersed in the
form globule to other continuous phase and whole
system is stabilized by addition of third agent called
as emulsifying agent

6. INTRODUCTION TO EMULSION
 ADVANTAGES
 mask the unpleasant taste
 economical
 improved bioavailability
 sustained release medication
 nutritional supplement
 diagnostic purpose
 topical use

7. INTRODUCTION TO EMULSION
 DISADVANTAGES
 short shelf life
 unstable
 care should be taken during handling and
storage

8. Types of emulsion
 1.O/W type of emulsion-
Oil is internal or discontinuous phase while
water is external or continuous phase
 2.W/O type of emulsion-
Water is internal or discontinuous phase
while oil is external or continuous phase

9. Types of emulsion

10. Types of emulsion
3. Microemulsion
Microemulsion are defined ‘as system of
water, oil, and amphiphile which is optically
isotropic and thermodynamically stable liquid
solution’
Droplet diameter 10-100nm
4.Multiple emulsion
it means emulsion in emulsion, it is
either o/w/o OR w/o/w

11. Difference between emulsion and
microemulsion

12. DIFFERENCES MACROEMULSION AND MICROEMULSION
SR.NO. MACROEMULSION MICROEMULSION
1. Thermodynamically unstable Thermodynamically stable
2. opaque Transparent
3. lyophobic Borderline betn lyophobic and
lyophillic
4. Droplet diameter 1-20mm Droplet diameter 10-100nm
5 Require intense agitation for their
formation
Generally obtained by gentle
mixing of ingredient
6. Interfacial tension high Interfacial tension ultra low
7. High viscosity Low viscosity with newtanion
behaviour
8. Inefficient molecular packing efficient molecular packing
9. Optically anisotropic Optically isotropic
10. No cosurfactant used cosurfactant used

13. INTRODUCTION TO MICROEMULSION
 History
In 1940 Hoar and Schulman first generated
microemulsion by titrating a milky emulsion with
hexanol
In 1959 schulman and co-worker coined term
microemulsion
 Definition
Microemulsion are defined ‘as system of
water, oil, and amphiphile which is optically isotropic
and thermodynamically stable liquid solution’

14. Advantages
 Thermodynamically stable, long shelf life
 Microemulsion act as super solvent for drug
 Potential reservoir of liphophilic or hydrophilic drug
 Due small droplet size it has large interfacial area of
globule so drug is rapidly released in external phase
when absorption takes place
 Ability to carry both hydrophilic and liphophilic drug
 Easy to prepare require no significant energy
 Low viscosity
 Helpful in test masking

15. Disadvantages
 Require large amount of surfactant and co
surfactant
for stabilizing droplets
 Limited solubility for high melting substances
 Stability influenced by enviournmental
parameter such as temperature and pH

16. Types of microemulsion systems
According to winsor, there are four types
 Oil-in-water microemulsion or winsor 1
Oil is internal phase, water is external phase and
system is stabilized by surfactant and co-surfactant
 Water-in-oil microemulsion or winsor 11
Water is internal phase, oil is external phase and
system is stabilized by surfactant and co-surfactant

17. Types of microemulsion systems
 Biocontinuousmicroemulsion or winsor 111
In this type amount of water and oil present are
nearly similar. An irregular channel of oil and
water are combined which looks like a sponge
It may show non-newtonian flow and plasticity
 Single phase homogeneous mixture or winsor 4
In this oil water and surfactant are homogenously
mixed

19. Components of microemulsion
 Oil phase
 Aqueous phase
 Surfactant
 Co-surfactant
 Oil phase
 most important excipient of formulation
 Required for solubilisation of lipophillic drug
 Example; mineral oils , cyclohexane, toluene,
silicone oil, esters of fatty acids

20. Components of microemulsion
 Aqueous phase
 It may contain hydrophilic active ingredient and
preservative
 Buffers can be used
 Surfactant
Surfactants are generally
 Ionic
 Non ionic
 Amphoteric

21. Components of microemulsion
 Non ionic surfactant generally used
 Cosurfactant
 Presence of surfactant allow interfacial film
sufficient flexibility to take up different curvature
 Sufficiently reduce interfacial tension to form
micro emulsion
 Increase fluidity of the interface
 Destroy liquid crystalline structure and gel
structure which would prevent formation of
microemulsion

22. Components of microemulsion
 Example ;
 short chain fatty alcohol such as hexanol,
benzyl alcohol ,esters of polyols derivatives of
glycerol and organic acids, Poloxamer ,
Polysorbate 80, Span 20
Cinnamic alcohol, Cinnamicaldehyde

23. Structure of Microemulsion

24. Construction of pseudoternary
phase diagram
 Pseudoternary phase diagrams comprises of oil,
Smix and water
 It is developed using the aqueous titration method
 The specific ratio of Smix, oil were taken in vial and
vortexed for five minutes followed by addition of
water with micropipette the addition of water was
continued until addition of one more drop produce
turbidity.
 They were also visually observed for phase clarity
and flowability.
 The volume of aqueous phase was noted and Phase
diagrams were then constructed

26. METHOD OF PREPARATION
 PhaseTitration Method
 Microemulsions are prepared by the
spontaneous emulsification method (phase
titration method)
It can be depicted with the help of phase
diagrams.
According to required type of microemulsion
ratio of oil, aqueous phase,smix are selected
and prepared using aqueous titration method

27. METHOD OF PREPARATION
 Phase Inversion Method
 Phase inversion of microemulsions occurs as a
result of addition of excess of the dispersed
phase or in response to temperature
During phase inversion drastic physical changes
occur including changes in particle size that can
affect drug release both in vivo and in vitro
This method is referred to as phase inversion
temperature (PIT) method. Instead of the
temperature, other parameters such as salt
concentration or pH value may be considered

29. Application of microemulsion in
delivery of drug
 Pharmaceutical Applications
 Oral delivery
Microemulsions have the potential to
enhance the solubilization of poorly soluble drugs
(particularly BCS class II or class IV) and overcome
the dissolution related bioavailability problems
These systems have been protecting the
incorporated drugs against oxidation, enzymatic
degradation and enhance membrane permeability.
Sandimmune Neoral(R) (Cyclosporine A),
Fortovase(R) (Saquinavir), Norvir(R) (Ritonavir) etc.
are the commercially available microemulsion
formulations

30. Application of microemulsion
in delivery of drug
 Parenteral delivery
 O/w microemulsions are beneficial in the
parenteral delivery of sparingly soluble drugs
where the administration of suspension is not
required
 They provide a means of obtaining relatively
high concentration of these drugs which
usually requires frequent administration
 they exhibit a higher physical stability in
plasma than liposome’s or other vehicles

31. Application of microemulsion
in delivery of drug
 Topical delivery
Direct delivery and targetability of the drug
to affected areas of the skin or eyes can be
achieved
Microemulsion are able to incorporate
both hydrophilic (5-flurouracil, apomorphine
hydrochloride, diphenhydramine hydrochloride,
tetracaine hydrochloride, methotrexate) and
lipophilic drugs (estradiol, finasteride,
ketoprofen, meloxicam, felodipine, triptolide)
and enhance their permeation through skin

32. Application of microemulsion
in delivery of drug
 Ophthalmic delivery
Microemulsions have emerged as a promising
dosage form for ocular use.
Chloramphenicol, an antibiotic used in the
treatment of trachoma and keratitis can be
formulated in microemulsion
microemulsion based dexamethasone eye
drops which showed better tolerability and
higher bioavailability.The formulation showed
greater penetration in the eye which allowed the
possibility of decreasing dosing frequency and
thereby improve patient compliance.

33. Application of microemulsion
in delivery of drug
 Nasal delivery
Recently, microemulsions are being
studied as a delivery system to enhance uptake
of drug through nasal mucosa. In addition with
mucoadhesive polymer helps in prolonging
residence time on the mucosa.
Lianly et al. investigated the effect of
diazepam on the emergency treatment of status
epilepticus. They found that the nasal absorption
of diazepam fairly rapid at 2 mg kg-1 dose with
maximum drug plasma concentration reached
within 2-3 min.

34. Application of microemulsion
in delivery of drug
 Drug targeting
Shiokawa et al. reported a novel microemulsion
formulation for tumor targeting of lipophilic
antitumor antibiotic aclainomycin A (ACM). They
reported that a folate-linked microemulsion is
feasible for tumour targeted ACM delivery. They
also reported that folate modification with a
sufficiently long PEG chain on emulsions is an
effective way of targeting emulsion to tumour
cells.

35. Application of microemulsion
in delivery of drug
 Periodontal Delivery
Periodontal disease is a collective term for a number
of progressive oral pathological afflictions like
inflammation and degeneration of the gums,
periodontal ligaments and its supporting bone. It is a
major cause of tooth loss.
The invention of Brodin et al. included a novel
pharmaceutical composition comprising local
anaesthetic in oil form, surfactant, water and
optionally a taste masking agent. The composition
was in the form of an emulsion or microemulsion

36. Application of microemulsion
in delivery of drug
 CellularTargeting
Monahan et al. included insertion of nucleic
acid into a reverse micelle for cell delivery.
They referred w/o microemulsions to as
reverse micelles advantage of the invention
was the use of reverse micelles for gene
delivery to the cells. The micelle containing
the

37. Application of microemulsion
in delivery of drug
 Microemulsions in Biotechnology
Enzymatic catalysis in microemulsions has
been used for a variety of reactions, such as
synthesis of esters, peptides and sugar
acetals transesterification; various hydrolysis
reactions and steroid transformation.The
most widely used class of enzymes in
microemulsion-based reactions is of lipases.

38. Application of microemulsion
 Other Applications
 Microemulsion in enhanced oil recovery.
 Microemulsions as fuels.
 Microemulsions as lubricants, cutting oils and
corrosion inhibitors
 Microemulsions as coatings and textile finishing.
 Microemulsions in detergency.
 Microemulsions in cosmetics.
 .

39. Application of microemulsion
 Microemulsions in environmental
remediation and detoxification.
 Microporous media synthesis (microemulsion
gel technique).
 Microemulsions in analytical applications.
 Microemulsions as liquid membranes.
 Novel crystalline colloidal arrays as chemical
sensor materials.

40. Application of microemulsion
 Microemulsions in agrochemicals.
 Microemulsions in food.

41. REFERENCES
1. Textbook of physical pharmacy by c.v.s.
Subhramnyam
2. Faizi muzaffar*, U. K. Singh, Lalit chauhan .
Review on microemulsion as futuristic drug
delivery . vol 5, issue 3, 2013 .
3. K.Senthil Kumar1*, D.Dhachinamoorthi1,
R.Saravanan1, UdayKumar Gopal1,
V.Shanmugam2 .microemulsions as carrier
for novel drug delivery: a review