419
this approach are the involvement of toxic organic solvents (monomers, initiator,
and surfactants), difficult processing, reactive residues, unreacted monomers, and
the risk of the formation of unwanted oligomers.
Interfacial Polymerization
It employs polyaddition and polycondensation methods. It has been extensively
employed for the preparation of microcapsules or oily core nanocapsules [45].
Interfacial Polycondensation
This technique involves the condensation of the hydrophilic and lipophilic monomer, e.g. diethylenetriamine and phthaloyl dichloride, respectively, to prepare nanocapsules either in the presence or absence of stabilizer. The internal phase is
water-miscible organic solvent having a hydrophobic polymer, whereas the external
phase contains a surfactant and hydrophilic monomer. The first step is emulsification and it comprises the spontaneous formation of an emulsion. The second step is
the polymerization step. Polycondensation reaction takes place at or in a thin region
adjacent to the interface of two immiscible liquids which then leads to the formation
of nanocapsules [46, 47]. This method involves less concentration of surfactants. By
varying, the concentration of the monomer thickness of nanocapsule can be modulated. The disadvantages of this modality are stated below:
• Low concentration of surfactants.
• Restricted to hydrophobic drugs encapsulation.
• Requires purification.
• Alteration of the thickness of the nanocapsule by fluctuating the monomer conc.
Miniemulsion Polymerization
This technique (Fig. 25.7) contains an initiator, water, monomer mixture, costabilizer, and stabilizer. Miniemulsion polymerization technique is different from
the emulsion polymerization in terms of using a low molecular weight compound as
the co-stabilizer to critically stabilize it and also involving ultrasound (a high-shear
device), to achieve an interfacial tension <0 and steady-state [48, 49].
It is an effective technique for the formulation of polymer nanostructures [50]
and has gained considerable attention. Emulsion polymerization appears similar to
micro-emulsion polymerization in starting conditions and the mechanism of polymerization as both techniques can formulate high molar mass colloidal polymer particles while kinetically completely different. The microemulsion polymerization
technique produces polymer particles having small size and significantly a smaller
number of chains in a particle (Table 25.1). This technique involves the addition of
25 Role of Nanoparticles in the Management of Metabolic Disorders
this approach are the involvement of toxic organic solvents (monomers, initiator,
and surfactants), difficult processing, reactive residues, unreacted monomers, and
the risk of the formation of unwanted oligomers.
Interfacial Polymerization
It employs polyaddition and polycondensation methods. It has been extensively
employed for the preparation of microcapsules or oily core nanocapsules [45].
Interfacial Polycondensation
This technique involves the condensation of the hydrophilic and lipophilic monomer, e.g. diethylenetriamine and phthaloyl dichloride, respectively, to prepare nanocapsules either in the presence or absence of stabilizer. The internal phase is
water-miscible organic solvent having a hydrophobic polymer, whereas the external
phase contains a surfactant and hydrophilic monomer. The first step is emulsification and it comprises the spontaneous formation of an emulsion. The second step is
the polymerization step. Polycondensation reaction takes place at or in a thin region
adjacent to the interface of two immiscible liquids which then leads to the formation
of nanocapsules [46, 47]. This method involves less concentration of surfactants. By
varying, the concentration of the monomer thickness of nanocapsule can be modulated. The disadvantages of this modality are stated below:
• Low concentration of surfactants.
• Restricted to hydrophobic drugs encapsulation.
• Requires purification.
• Alteration of the thickness of the nanocapsule by fluctuating the monomer conc.
Miniemulsion Polymerization
This technique (Fig. 25.7) contains an initiator, water, monomer mixture, costabilizer, and stabilizer. Miniemulsion polymerization technique is different from
the emulsion polymerization in terms of using a low molecular weight compound as
the co-stabilizer to critically stabilize it and also involving ultrasound (a high-shear
device), to achieve an interfacial tension <0 and steady-state [48, 49].
It is an effective technique for the formulation of polymer nanostructures [50]
and has gained considerable attention. Emulsion polymerization appears similar to
micro-emulsion polymerization in starting conditions and the mechanism of polymerization as both techniques can formulate high molar mass colloidal polymer particles while kinetically completely different. The microemulsion polymerization
technique produces polymer particles having small size and significantly a smaller
number of chains in a particle (Table 25.1). This technique involves the addition of
25 Role of Nanoparticles in the Management of Metabolic Disorders