Development of cephalexin-loaded poly(ethyl cyanoacrylate) colloidal nanospheres

This article considers the preparation and physicochemical characterization of a novel colloidal formulation of the β-lactam antibiotic cephalexin, loaded in poly(ethyl cyanoacrylate) colloidal nanospheres. The drug was loaded by means of drug incorporation in the interior of poly(ethyl cyanoacrylate) particles during the polymerization of the respective monomer in aqueous medium. The obtained colloids were characterized by scanning electron microscopy, dynamic and electrophoretic light scattering, Fourier transform infrared and nuclear magnetic resonance spectroscopy. It was found that the drug loading efficiency depends on the initial concentration of monomer and cephalexin in the polymerization medium. The average size of cephalexin-loaded particles was around 400 nm and did not depend significantly on the concentrations of drug and monomer. Drug-loaded particles with drug content as high as 21% (w/w) were prepared. The drug release kinetics was studied in physiological phosphate-buffered saline. It was found that a biexponential model could describe well the experimental release kinetics.