Nanoparticle emulsification

Nature of nanoparticle Emulsification method Nature of nanoemulsion Monomers Surfactants Polymerization and emulsification parameters Particle size (nm) References... 

A similar technique, the so-called spontaneous emulsification solvent diffusion method, is derived from the solvent injection method to prepare liposomes [161]. Kawashima et al. [162] used a mixed-solvent system of methylene chloride and acetone to prepare PLGA nanoparticles. The addition of the water-miscible solvent acetone results in nanoparticles in the submicrometer range this is not possible with only the water-immiscible organic solvent. The addition of acetone decreases the interfacial tension between the organic and the aqueous phase and, in addition, results in the perturbation of the droplet interface because of the rapid diffusion of acetone into the aqueous phase. 

The drawbacks of the W/O emulsification method include the use of large amounts of oils as the external phase, which must be removed by washing with organic solvents, heat stability problems of drugs, possible interactions of the cross-linking agent with the drug, and, as with all nanoparticles prepared by emulsification techniques, a fairly broad particle size distribution. 

Biocompatible silica nanoparticles prepared by analogous sol formation followed by emulsification and doped with the antibiotic... 

Trotta M., Debernardi R, and Caputo O., Preparation of solid lipid nanoparticles by a solvent emulsification-diffusion technique, Int. J. Pham., 251, 153, 2003. 

Spontaneous emulsification and solvent diffusion method Solid lipid nanoparticles 20-80 nm Horn and Rieger, 2001 Cui et al., 2006 Ribeiro et al., 2008... 

The solvent emulsification/evaporation method involves lipid precipitation in O/W emulsions. Solid lipids are dissolved in a water-immiscible organic solvent (e.g., cyclohexane) followed by emulsification in an aqueous medium. Upon evaporation of the solvent, the nanoparticle dispersion is formed due to lipid precipitation. Residue of organic solvents is the major problem of this method [94], However, the microemulsion and solvent emulsification/evaporation methods can be performed conveniently in the laboratory without specific apparatuses. 

Emulsion Solvent Evaporation The basic concept of the emulsion solvent evaporation technique producing nanoparticles is very straightforward. The particles are formed as an emulsion of a polymer-surfactant mixture and dispersed in an organic solvent. The solvent is then evaporated to leave behind the individual emulsion droplets which form stable free nanoparticles [203], This method is far easier and more preferable over methods such as spray drying and homogenization and operates under ambient conditions and mild emulsification conditions. The size and composition of the final particles are affected by variables such as phase ratio of the emulsion system, organic solvent composition, emulsion concentration, apparatus used, and properties of the polymer [204],... 

Keywords Cyclodextrin silicone nanoparticle spontaneous emulsification drug... 

Submicronic particles (nanoparticles) produced in that way allowed the encapsulation of the griseofulvin antifungal substance up to the 1 1 stoichiometry with respect to the P-cyclodextrin. A simple oil-in-water emulsion could not achieve such encapsulation because P-cyclodextrin was not soluble in common oils this was shown with silicone oil in the present study. The spontaneous emulsification process used for the preparation of the particles also allowed the easy encapsulation of the sparingly soluble griseofulvin. 

The pharmaceutical field is among those most widely exploiting ultrasonic emulsification (mainly for the preparation of emulsion-based drugs). Thus, US emulsification has been recently used to prepare biodegradable nanoparticles that can in turn be used to obtain drug-loaded biodegradable microspheres. The method involves ultrasonic emulsification in a continuous flow system to obtain suspended nanoparticles, followed by collection of the particles, solvent extraction and evaporation [49]. 

Although water-immiscible solvents display low solubility in water, there is some amount of solubility. The solvent diffusion/emulsification method exploits this for the production of nanoparticles. In this technique, drug and polymer are dissolved in an organic, water-immiscible solvent that is emulsified into an aqueous solution containing emulsifiers and stabilizers. The emulsion is then diluted with water to increase the level of organic solvent, which can be dissolved in the... 

A novel nanoparticulate lipid-based carrier system was developed by Mumper et al. at the University of Kentucky. ° This carrier system is composed of a lipophilic-emulsifying wax such as cetyl alcohol/ polysorbate 60 and other surfactants such as Brij 72, Brij 78, and Tween 80. The nanoparticles were formed through a warm microemulsion technique where encapsulates have included paclitaxel and plasmid DNA. The emulsification process is spontaneous, and cooling of the emulsion causes solidification of the nanoparticle-containing drug. This novel carrier has shown high efficiency in drug delivery across the blood-brain barrier. 

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