Effect of solvent on the preparation of surfactant-free poly(DL-lactide-co-glycolide) nanoparticles and norfloxacin release characteristics

The surfactant-free nanoparticles of poly(DL-lactide-co-glycolide) (PLGA) w ere prepared by dialysis method without surfactant and physicochemical prop erties such as particle size and drug contents were investigated against us ed initial solvent. The size of PLGA nanoparticles and drug contents were s ignificantly changed by used initial solvent. The size of PLGA nanoparticle s prepared from dimethylacetamide (DMAc), dimethylformamide (DMF), and dime thylsulfoxide (DMSO) as a initial used solvent was smaller than that of ace tone. Selected initial solvent used to dissolve the copolymer significantly affects the size of nanoparticles and drug contents. It was shown that PLG A nanoparticles have spherical shapes from the results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. It was thought that surfactant-free nanoparticles of PLGA entrapping norflo xacin (NFX) has nice drug loading capacity without free-drug on the surface of nanoparticles through the analysis of X-ray powder diffraction. From th ese results, it was showed the potential that the PLGA nanoparticles could be formed successively by dialysis method without surfactant. Release kinet ics of NFX used as a model drug was governed by not only drug contents but also particle size parameter. The higher the drug contents and the larger t he particle size resulted in slower the drug release. (C) 2000 Elsevier Sci ence B.V. All rights reserved.