computer in pharmaceutical formulatation,development in pharmaceutical emulsion microemulsion as drug carriers

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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