title: Using different structure types of microemulsions for the preparation of poly(alkylcyanoacrylate) nanoparticles by interfacial polymerization.
abstract: A phase diagram of the pseudoternary system ethyloleate, polyoxyethylene 20 sorbitan mono-oleate/sorbitan monolaurate and water with butanol as a cosurfactant was prepared. Areas containing optically isotropic, low viscosity one-phase systems were identified and systems therein designated as w/o droplet-, bicontinuous- or solution-type microemulsions using conductivity, viscosity, cryo-field emission scanning electron microscopy and self-diffusion NMR. Nanoparticles were prepared by interfacial polymerization of selected w/o droplet, bicontinuous- or solution-type microemulsions with ethyl-2-cyanoacrylate. Morphology of the particles and entrapment of the water-soluble model protein ovalbumin were investigated. Addition of monomer to the different types of microemulsions (w/o droplet, bicontinuous, solution) led to the formation of nanoparticles, which were similar in size ( approximately 250 nm), polydispersity index ( approximately 0.13), zeta-potential ( approximately -17 mV) and morphology. The entrapment of the protein within these particles was up to 95%, depending on the amount of monomer used for polymerization and the type of microemulsion used as a polymerization template. The formation of particles with similar characteristics from templates having different microstructure is surprising, particularly considering that polymerization is expected to occur at the water-oil interface by base-catalysed polymerization. Dynamics within the template (stirring, viscosity) or indeed interfacial phenomena relating to the solid-liquid interface appear to be more important for the determination of nanoparticle morphology and characteristics than the microstructure of the template system.
authors.affiliation: New Zealand National School of Pharmacy, University of Otago, P.O. Box 913, Dunedin, New Zealand. karen.krauel@stonebow.otago.ac.nz
authors.forename: K
authors.initials: K
authors.lastname: Krauel
authors.forename: N M
authors.initials: NM
authors.lastname: Davies
authors.forename: S
authors.initials: S
authors.lastname: Hook
authors.forename: T
authors.initials: T
authors.lastname: Rades
mesh_terms: D020001:1-Butanol / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D002725:Chloroform / Q000737:chemistry; D003487:Cyanoacrylates / Q000138:chemical synthesis / Q000737:chemistry*; D004337:Drug Carriers; D004553:Electric Conductivity; D004655:Emulsions / Q000737:chemistry; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006601:Hexoses / Q000737:chemistry; D049329:Nanostructures / Q000648:ultrastructure; D010047:Ovalbumin / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011136:Polysorbates / Q000737:chemistry; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D003487:Cyanoacrylates; D004337:Drug Carriers; D004655:Emulsions; D005456:Fluorescent Dyes; D006601:Hexoses; D011108:Polymers; D011136:Polysorbates; D014867:Water; C029054:ethyl 2-cyanoacrylate; C014822:sorbitan monolaurate; D002725:Chloroform; D020001:1-Butanol; D010047:Ovalbumin; D016650:Fluorescein-5-isothiocyanate