Microemulsion

Presented By:

Mr.Sudarshan B. Aher

T.Y.B.Pharm

Roll No.05

Guided By:Mr. S. B.Gondkar

M.Pharm (Pharmaceutics)

R.G.SAPKAL COLLEGE OF PHARMACY,ANJANERI,NASHIK

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LOGO1. Introduction1. Introduction

2. Basic Concepts2. Basic Concepts

3. Characteristic & Properties3. Characteristic & Properties

4.Physicochemicalcharacteristics

4.Physicochemicalcharacteristics

Outline

5. conclusion

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History

1928 1943 1959 1970

The first commercialmicroemulsion by Radawald.

Was recognized as special kindof colloidal dispersion before the work of Schulman.

Be named microemu-lsions in 1959.

1970, research in microemu-lsion reached a large scale.

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What is Micro Emulsion?

Surfactant

Oil Phase

Water Phase

Co-Surfactant

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Concept of Micro Emulsion

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

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. Definition:

“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)

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The advent of micro emulsion has lead to the improvement in many fields.

Micro Emulsion

Foodpharmacy

…

Daily use Chemistry

Oil Recovery

Catalyst

Micro Emulsion in Our Life

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Characteristic Properties

PropertiesPropertiesBehaves like Newtonian fluids

Characteristic Interfacial tension

Thermodynamically stable, contrary to emulsions

Large value of face area lead to the betterfunction of transport of heat and substance

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Surfactants:Definition:

A surfactant is an organic molecule that adsorbs at an interface and lowers the surface (or interfacial) tension. It consists of two well-defined moieties, one is water-soluble (hydrophilic part), and the other is oil-soluble (hydrophobic part). The hydrophilic part of the surfactant is referred to as the head group and it is usually either an ionic group, or a non-ionic polar group.

Example:

The hydrophobic part is referred to as the tail, and usually it is a single or double, straight or branched, aliphatic hydro- or halo-carbon chain(s). Surfactant tails may also contain aromatic group(s).

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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.

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Uses of Micro Emulsion

Microemulsions ave many commercially important uses. The fluid used in some dry cleaning processes is a water-in-oil

microemulsion. Some floor polishes and cleaners, personal care products,

pesticide formulations are actually microemulsions. Much of the work done on these systems have been motivated by

their possible use to mobilize petroleum trapped in porous sandstone for enhanced oil recovery.

Microemulsions in Pharmaceuticals:

.Widely used in pharmaceutical preparations.

. Used as injection solutions, as they are miscible with blood in any ratio.

. In contrast to emulsions, microemulsions cause minimum immune reactions or fat embolism.

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Uses of Micro Emulsion

More and more applications in our life

Nano Science

Makeup

Depurative

Extraction

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Physicochemical characteristics

Determination of pH

Viscosity

Centrifugation

Spreadability

Skin irritation test

Optical transparency

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Comparison With Emulsions And Microemulsion

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Emulsions Microemulsions

1.Emulsions consist of roughly spherical droplets of one phase dispersed into the other.

1.They constantly evolve between various structures ranging from droplet like swollen micelles to bicontinuous structure.

2. Droplet diameter: 1 – 20 mm. 2. 10 – 100 nm.

3. Most emulsions are opaque (white) because bulk of their droplets is greater than wavelength of light and most oils have higher refractive indices than water.

3. Microemulsions are transparent or translucent as their droplet diameter are less than ¼ of the wavelength of light, they scatter little light.

4. Ordinary emulsion droplets, however small exist as individual entities until coalesance or ostwald ripening occurs.

4. Microemulsion droplet may disappear within a fraction of a second whilst another droplet forms spontaneously elsewhere in the system.

5. They may remain stable for long periods of time, will ultimately undergo phase separation on standing to attain a minimum in free energy. They are kinetically stable thermodynamically unstable

5. More thermodynamically stable than emulsions and can have essentially infinite lifetime assuming no change in composition, temperature and pressure, and do not tend to separate.

6. They are lyophobic. 6. They are on the borderline between lyophobic and lyophilic colloids.

7. Require intense agitation for their formation. 7. Generally obtained by gentle mixing of ingredients.

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Summary:

Microemulsions are optically isotropic and thermodynamically stable liquid solutions of oil, water and amphiphile. Microemulsions are readily

distinguished from normal emulsions by their transparency, low viscosity and more fundamentally their thermodynamic stability.

Conclusion:

Drug delivery through microemulsions is a promising area for continued research with the aim of achieving controlled release with enhanced bioavailability and for drug targeting to various sites in the body.

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LOGOMarketed Preparations:

1.Aceclofenac Transdermal Microemulsion,

2.Ketoprofen Microemulsion,

3.Topical microemulsion of Nimesulide,

4.Vaginal gel of Fluconazole,

5. Topical Ibuprofen gel (Solvium),

6. Propofol containing anesthetic .

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LOGOREFRENCES:

•Pharmaceuticals dosage form: disperse system volume1st,second edition, reviced and expended edited by Hebert D. Liberman, Martine M. Rieger and Gilbert S. bankar page no 57-61.

•Pharmaceuticals dosage form: disperse system volume2nd,second edition, reviced and expended edited by Hebert D. Liberman, Martine M. Rieger and Gilbert S. bankar page no 49-51,67-74,95-96,109.

•The theory & practice of industrial pharmacy ,leon lachman,Herbert a. Lieberman special edition 2009, CBS publisher & distributors pvt. Ltd page no 503-529

•Aulton,pharmaceutics the design and mfg of medicine by micheal aulton 3

editionchurchil living store Elsevier.page no. 92-93, 391, 530-536,594.

•http://en.wikipedia.org/wiki/microemulsion.

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Thank you!SUDARSHAN B. AHERT.Y.B.PHARMACY