The document discusses the role of computers in optimizing pharmaceutical formulations, focusing on emulsions and microemulsions as drug carriers. It outlines the definitions, types, stability issues, and preparation methods for emulsions and microemulsions, highlighting their applications and evaluation techniques. The content emphasizes the significance of emulsifying agents and theories of emulsification in enhancing stability and effectiveness in pharmaceutical applications.

1. COMPUTERS IN
PHARMACEUTICAL
FORMULATIONS
Presented By
Sujitha Mary
M Pharm
St Joseph College Of Pharmacy
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2. CONTENTS
 Computers in pharmaceutical formulations
 Development of pharmaceutical emulsions
 Microemulsions as drug carriers
 Reference
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3. INTRODUCTION
Formulation and development is a process
of selection of component and processing
 Various technique such as design of experiments are
implemented for optimization of formulation and
processing parameter
 Traditionally optimization refers to changing one
variable at a time
 Many times finding the correct answer is not simple .
In such cases use of computer tools is the best way
to solve problem
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4. DEVELOPMENT OF
PHARMACEUTICAL EMULSIONS
 Definition
An emulsion is a thermodynamically
unstable system containing mixture of two or more
immiscible liquids which is stabilized by adding
emulsifying agent.
 Phases of emulsion
Discontinuous phase
Continous phase
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5. TYPES OF EMULSIONS
 Based on dispersed phase
Oil in water(o/w)
Water in oil (w/o)
Water in oil in water(w/o/w)
 Based on size of liquids
Macroemulsions
Microemulsions
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6. EMULSIFYING AGENTS
An emulsifying agent is any material
that enhances the stability of an emulsion
 Mainly 3 types
Surfactants- Eg: SLS, Cetrimide
Hydrocolloids- Eg: Acacia, Tragacanth
Finely divided solids- Eg : Bentonite
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7. THEORIES OF
EMULSIFICATION
 Film theory:
The added emulsifying agent forms a mechanical film
by getting adsorption
 Viscosity theory:
↑in viscosity,↑in stability
 Wedge theory:
Monovalent soap gives o/w emulsion,divalent soap
gives w/o emulsion
 Interfacial theory:
The added emulsifying agent reduces the interfacial
tension
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8. STABILITY OF EMULSIONS
Most common stability problems are
 Creaming and sedimentation:
As the droplets are subjected to gravity
force,they tend to move upward (creaming) or
downward(sedimentation)
 Cracking or coalescence:
Is the fusion of 2 or more droplets of the
disperse phase forming one droplet
 Phase inversion:
Emulsion changes from one type to another
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9. METHODS TO ENHANCE
STABILITY
 Globule size:
smaller particles have slower creaming or
sedimentation
 Viscosity of continuous phase:
↑in viscosity ↑stability
 Using emulsifying agent:
Enhance viscosity,reduce interfacial tension
 Storage of temperature:
↑ in temp,↓ stability
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10. METHODS FOR EVALUATION OF
STABILITY OF EMULSIONS
 Size frequency analysis by microscopy
 Velocity of craming
 Globule size analysis
 Turbidimetric analysis
 Conductivity testing
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11. METHODS OF
PREPARATION
 Dry gum method
• Triturate emulsifier+oil
• Add water
• Triturate and form primary emulsion
• Add remaining qty of water
 Wet gum method
• Triturate gum+water
• Add oil and form primary emulsion
• Add remaining qty of water
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12. METHODS OF
PREPARATION
 Bottle or Forbes bottle method
Gum+oil
↓
shake
↓
Add water
↓
Shake to form primary emulsion
↓
Add remaining qty of water
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13. APPLICATIONS OF
EMULSIONS
 Oral administarion of water insoluble liquids
 IV administration of API as an emulsion(Taxol)
 For external use(lotions,liniments)
 Emulsions in aerosol can be used to produce
foam
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14. MICROEMULSIONS AS DRUG
CARRIERS
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15. MICROEMULSIONS
Microemulsions are
thermodynamically stable,optically
transparent,isotropic dispersions of
aquous and hydrocarbon liquids stabilized
by an interfacial film of surfactants
molecule
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16. MICROEMULSION AS A DRUG
CARRIER SYSTEM
 Improved drug solubilization
 Long shelf life
 Ease of preparation
 Improved bioavailability
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17. DISADVANTAGES
 Stability is influenced by environmental
parameters such as temperature and ph
 Limited solubilizing capacity for high melting
substances
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18. TYPES OF
MICROEMULSIONS
 Direct microemulsion:
Droplets are dispersed in the
continuous aquous phase
 Reversed microemulsion:
Water droplets are dispersed in the
continuous oil phase
 Bicontinuous microemulsion:
Micro domains of oil and water are
interdispersed within the system
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19. THEORIES OF
MICROEMULSION
 Thermodynamic theory
The free energy of microemulsion formation can be
dependent on the extent to which surfactant lowers the surface
tension of oil-water interface
DGF=ˠDA-TDS
 Solubilization theory
Formation of microemulsion by micelles gradually
become larger and swells to a certain size range results
 Interfacial theory
Microemulsion is capable of forming negative
interfacial tension
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20. COMPONENTS OF
MICROEMULSION
 Oil – Eg:Isopropylmyristate,olive oil
 Surfactant –Eg:Tween80,Tween20
 Cosurfactants-Eg:Propyleneglycol,Ethanol
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21. PREPARATION
 Drug has to dissolve in to oil phase of microemulsion
 Water phase is combined with surfactant and cosurfactant
 The amount of surfactant and cosurfactant to be added in the oil
phase is determined with the help of pseudoternary phase diagram
 Ultrasonicator can finally used to achieve the desired range for the
dispersed phase
 It is then allow to equilibrate
 Gel may be prepared by the addition of gelling agent to above
microemulsion
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22. APPLICATIONS
 Dry cleaning process
 Pesticide formulation
 Floor polishers and cleaners
 Cutting oils
 In industry for the synthesis of polymers
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23. REFERENCE
 www.slideshare .com
 Textbook of Industrial Pharmacy by
Liebermann
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