Freeze-fracture electron microscopy and light scattering studies on polyethylcyanoacrylate nanocapsule colloidal suspensions

Summary

Nanocapsule preparative procedures are able to change the availability of drugs from delivery devices. In particular, the influence of the organic solvent, used in the interfacial polymerisation process, on the shape, mean particle size, size distribution and type of colloidal suspension was investigated. The organic solvents employed in the preparation of PECA nanocapsules were ethanol, acetone or acetonitrile. A non-ionic surfactant (Pluronic F68) was used during the preparation process. The amount of monomer represented another variable, capable of influencing the final carrier properties of PECA nanocapsules. The presence of ethanol achieved the formation of both nanoparticles and nanocapsules. However, the presence of acetone or acetonitrile achieved not only a highly homogeneous size colloidal system, but also the formation of only one type of PECA nanosphere (nanocapsule). The different amount of monomer led to the formation of nanocapsules with a wall thickness proportional to the initial concentration of the polymerising agent.