Polyalkyl cyanoacrylate nanocapsules.

In-situ polymerized methyl cyanoacrylate (MCA), ethyl cyanoacrylate (ECA), and butyl cyanoacrylate (BCA) were used to prepare nanocapsules of fluorescein or doxorubicin as markers by a w/o emulsion interfacial polymerization technique. Different concentrations of MCA were also used to show the effect of monomer concentration. The nanocapsules were characterized by electron microscopy, particle size analysis, holding capacity and in-vitro release of the marker substances. After selection of the polymerization solvent system, nearly spherical nanocapsules were obtained using each of the monomers. Most of the nanocapsules prepared were in the particle size range 500-1500 nm diameter. They were able to hold 55-74% of the marker initially present in aqueous solution. In-vitro dissolution studies showed that release of marker was retarded variably in an increasing order from nanocapsules containing MCA, ECA then BCA. Increasing the concentration of the monomer in the nanocapsules led to retardation of marker release.