02347naa a2200253 a 450000100080000000500110000800800410001902400350006010000250009524500960012026000090021652015960022565300170182165300190183865300190185765300140187670000220189070000200191270000200193270000230195270000280197570000200200377300700202320752792022-05-20       2017    bl uuuu     u00u1 u    #d7 a10.1007/s11051-017-3968-62DOI1 aDUARTE JUNIOR, A. P.  aChitosan nanoparticles as a modified diclofenac drug release system.h[electronic resource]  c2017  aThis study evaluated a modified nanostructured release system employing diclofenac as a drug model. Biodegradable chitosan nanoparticles were prepared with chitosan concentrations between 0.5 and 0.8% ( w/ v) by template polymerization method using methacrylic acid in aqueous solution. Chitosan-poly(methacrylic acid) (CS-PMAA) nanoparticles showed uniform size around 50?100 nm, homogeneous morphology, and spherical shape. Raw material and chitosan nanoparticles were characterized by thermal analysis, Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM), confirming the interaction between chitosan and methacrylic acid during nanoparticles preparation. Diclofenac sorption on the chitosan nanoparticles surface was achieved by incubation in water/ethanol (1:1) drug solution in concentrations of 0.5 and 0.8 mg/mL. The diclofenac amount sorbed per gram of CS-PMAA nanoparticles, when in a 0.5 mg/mL sodium diclofenac solution, was as follows: 12.93, 15, 20.87, and 29.63 mg/g for CS-PMAA nanoparticles 0.5, 0.6, 0.7, and 0.8% ( w/ v), respectively. When a 0.8 mg/mL sodium diclofenac solution was used, higher sorption efficiencies were obtained: For CS-PMAA nanoparticles with chitosan concentrations of 0.5, 0.6, 0.7, and 0.8% ( w/ v), the sorption efficiencies were 33.39, 49.58, 55.23, and 67.2 mg/g, respectively. Diclofenac sorption kinetics followed a second-order kinetics. Drug release from nanoparticles occurred in a period of up to 48 h and obeyed Korsmeyer-Peppas model, which was characterized mainly by Fickian diffusion transport.  aBiopolímero  aNanopartícula  aNanotecnologia  aQuitosana1 aTAVARES, E. J. M.1 aALVES, T. V. G.1 aMOURA, M. R. de1 aCOSTA, C. E. F. da1 aSILVA JÚNIOR, J. O. C.1 aCOSTA, R. M. R.  tJournal of Nanoparticle Researchgv. 19, n. 8, article 274, 2017.