2. • MICELLES:
• It is lipid molecules that arrange themselves in a spherical form in aqueous
solution.
• Micelles are Amphiphilic in nature.
• Made up of polar head and Non-polar chain.
• AGGRERGATION NO
• It is number of molecules present in a micelles when critical micelle
concentartion has been reached.
• CMC:
• The concentration of surfactant above which micelles form is called Critical
Micelles Concentration(CMC).
• METHODS OF PREPARATION
• Direct Dissolution
• Indirect method by using organic solvent
• Dialysis Method
• Solution Casting Method
• Freeze Drying Method
3. • METHODS OF PREPARATION
• Direct dissolution:
• Direct dissolution of drug and co-polymer in water. It is simple
technique. Drug loading efficiency is low.
• Indirect method by using organic solvent:
• This method applied to amphiphilic co-polymer which is readily soluble in
water.
• Common organic solvent used in this method, eg. DMSO, Acetone etc.
• Dialysis
• Solution of drug and co-polymer 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.
This method suitable for core forming blocks which are long & more
hydrophobic.
• Dialysis process often take more than 36 hours for efficient drug loading.
4. • METHODS OF PREPARATION
Solution casting:
• Volatile organic solvent used to dissolve the co-polymer & drug.
• After complete evaporation of solvent there is thin film obtained.
• Drug loaded micelles are obtained by reconstitution of film in water.
• Lyophilization method:
• Water + Tert-Butanol mixture is used for dissolving drug as well as co-
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
