INFLUENCE OF THE PREPARATION CONDITIONS ON POLY(ETHYLCYANOACRYLATE) NANOCAPSULE FORMATION

Poly(ethylcyanoacrylate) (PECA) nanocapsules suitable for use as drug delivery systems were prepared by in situ polymerization, adding the m onomer to an organic phase and subsequent mixing of the latter to an a queous phase containing a nonionic surfactant. Different preparation c onditions have been able to influence the final PECA nanocapsule collo idal suspension. In particular, the kind of organic solvent caused the formation of either simple PECA nanocapsule suspensions (aprotic full y water-miscible solvents) or PECA nanoparticle colloidal suspensions consisting of nanospheres and nanocapsules (protic water-miscible solv ent). Both mechanisms, the interfacial precipitation of a pre-formed p olymer and the interfacial polymerization, could play a significant ro le in nanocapsule formation. Also other variables, such as the kind of the nonionic surfactant and the monomer concentration, affected in di fferent ways the nanocapsule formation process.