Page 42 - controlled drug delievery
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Microencapsulation
• Involves enclosing the drug or drug dispersion by a polymer
membrane.
• Microencapsulation methods include:
–Interfacial polymerization.
– Coacervation.
–Complex coacervation.
Interfacial polymerization
The process takes place in an o/w emulsion
1. Drug dispersion + oil soluble monomer ----------oil phase
2. Water soluble monomer----------aqueous phase
3. Polymerization reaction takes place at the oil/water interface
e.g. NH2-R-NH2 + ClCO-R’-COCl ----------- ClCO-R’-CONH-R-NH2 + HCL
Diamine Acid chloride Polyamide
