FORMATION AND CHARACTERIZATION OF CYCLOSPORINE-LOADED NANOPARTICLES

The commercially available formulations of cyclosporine (cyclosporin A , CyA) are associated with acute hemodynamic changes that result in hi gh nephrotoxicity. Among colloidal vectors, nanoparticles (NPs) are re ceiving much attention as potential drug carriers that would avoid the therapeutic risks of conventional formulations. Two different mechani sms for obtaining polymeric NPs loaded with CyA were studied with rega rd to their preparation and physicochemical characterization. isobutyl -2-cyanoacrylate monomer (IBCA) was polymerized, whereas poly-E-caprol actone (PCL, a preformed polymer) was precipitated; both reactions too k place in an aqueous medium containing Pluronic F-68 (polyoxypropylen e polyoxyethylene block copolymer) as a surface active agent. The enca psulation efficiencies were 78.49 +/- 5.87 and 84.85 +/-5.02%, respect ively, and they remained stable over a wide range of drug concentratio ns. The polymeric NP had average sizes of 81 +/- 25 and 95 +/- 25 nm f or poly-IBCA and PCL, respectively, as confirmed by photon correlation spectroscopy. Poly-IBCA NPs were built from oligomers with molecular weights of 157 to 2644 that joined to form a polymeric nanomatrix. In vitro activity of the drug and the carrier was tested by inhibition of lymphocyte proliferation induced by Concanavalin A. Drug-loaded PCL N Ps and free CyA inhibited lymphocyte proliferation by 91.40 and 86.19% , respectively. However, drug-free NPs also exhibited statistically si gnificant (p < 0.05) immunosuppressive activity.