polymeric micelle, method of preparation and characterization methods and apllication of polymeric micelle in pharmacy and drug delivery system.

1. MAHARAJA AGRASEN
UNIVERSITY(SCHOOL OF PHARMACY)
POLYMERIC MICELLE
Submitted to: Submitted by:
Mr. Hans Raj Sagar Kundlas
(Astt. Professor) MAU16BPH049
B. Pharmacy
(6th semester)
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2. • Polymeric micelles are formed from self-
aggregation of amphiphilic block / graft co-
polymers with the hydrophobic part of the
polymer on the inside (core) and hydrophilic on
the outside (shell).
• In drug delivery, PM are classified under the
“Nano carriers”.
• A polymeric micelle usually consists of several
hundred block copolymers and has a diameter of
about 20-50 nm
INTRODUCTION
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3. STRUCTURE
OF
POLYMERIC
MICELLE
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4. • Self-assembled supramolecular core-shell structure.
• Core is a dense region consisting of the hydrophobic part of
the amphiphilic polymer.
• Core serves as a reservoir for drugs with low aqueous
solubility.
• Shell consisting hydrophilic portion of the co-polymer.
• The morphology of micelles is the hydrophilic–hydrophobic
balance of the block copolymer defined by the hydrophilic
volume fraction, f.( f>45% form PM)
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5. MECHANISM OF
MICELLIZATION
Amphiphilic block or graft copolymers behave in the same manner as that of
conventional amphiphiles and in aqueous solution, above CMC, it forms PM.
CMC (critical micelle concentration) it is the minimum concentration required
by amphiphilic molecule to start micellization .
CMT( critical micelle temperature) The temperature below which amphiphilic
molecules exist as unimers and above which as aggregates.
Aggregation number is the number of molecules present at CMC.
They form spherical structure in order to reduce the free energy of system.
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6. TYPES OF
POLYMERIC
MICELLE
• On the basis of the type of intermolecular forces governing
the segregation of the core segment from the aqueous
Environment, those formed by ;
1. Hydrophobic interaction – these are Conventional micelles
2. Electrostatic interaction – these are Polyion complex
micelle
3. Metal complexation – these are Noncovalently Connected
Polymeric Micelles .
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7. METHOD OF
PREPARATION
Can be prepared mainly by three common
approach:
Direct dissolution
Solvent casting technique
Dialysis
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8. CONTINUED:
Direct dissolution
Direct dissolution of drug
and copolymer in water
It is simple technique
Drug loading efficiency is
low
Solvent casting
Volatile organic solvent
used to dissolve the
copolymer & drug
After complete
evaporation of solvent
there is thin film obtained
Drug loaded micelles are
obtained by reconstitution
of film in water
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9. • Dialysis
• Solution of drug and copolymer in organic solvent are placed in dialysis bag and
the solvent is exchanged with water by immersing the bag into water inducing
micelle assembly.
• This method is suitable for loading of drug which has poor solubility
• Suitable for core forming blocks are long & more hydrophobic
• Dialysis process often take mare than 36 hours for efficient drug loading
• Lyophilization method
• Water tert. Butanol mixt. Is used for dissolving drug as well as polymer and then
solution is polymerised
• Drug loaded polymeric micelles obtained by redispersing the lyophilized product in
suitable vehicle
• It is simple and cost effective method
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10. CHARACTERIZATION
OF POLYMERIC
MICELLES
CMC:
It is the key parameter in the formation & the static
stability of polymeric micelles
Con. of amphiphilic polmer in aqueous media
if , >cmc – exhist in t5he form of polymeric micelles
if , < cmc – micelles may collapse
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11. CONTI.
• CMC determination
• Surface tension measurement
• Chromatography
• Light scattering
• DSC
• Viscometry
• Pyren as fluorscent probe
• Size & shape (geometry)
• The polydispersity index of prepared structure is
• obtained by examining the micellar solution using
• light scattering techniques
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12. CONTI.
Monodisperse micelles
If produce blue color indicate good micellar preparation
If produce white color indicate aggregation
Scanning electron microcopy & transmission electronmicroscopy has
been used for size and shape determination
In-vitro drug release behavior
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13. • Solubilization
• Solubilization process leads to enhance solubility of water
insoluble molecule in water
• Non-osized polymeric micelles elevate GI uptake & enhance
its bioavailability
• Targetting delivery of drug
• It is usually achieved by one of the following approaches
• Permeability enhancer
• Retention effect
• Stimuli sensitivity
• internal : pH, enzymes
• external : temp. ,light, ultrasound, magnetic field
• Liganding to micelle surface
• Immunomicelles
APPLICATIONS
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