Nylon fibers coated with diclofenac: adsorption properties

Dried gauzes properly coated with anti-inflammatory drugs could be helpful in providing topical treatment in inflammatory process. Therefore, thermodynamic of adsorption of Diclofenac Sodium, over Nylon fibers, as a function of concentration, temperature, and pH of the medium, have been studied. Maximum amount adsorbed in the best conditions tested, pH 5.6, 323 K and initial concentration of 150 mg/L has been 2.6 mg/g. Isotherm adsorption data were well fitted to the Langmuir and Freundlich model; therefore, multilayer formation must be considered. Negative and low values of free-energy change, ?17.9 kJ/mol and ?15.9 kJ/mol, in addition to moderate value of activation energy 13.14 kJ/mol point to physical interactions governing the process that, besides, is exothermic with negative enthalpy-change, ?43.44 kJ/mol, and also follows pseudo-first order kinetic model that is typical of this interaction. Desorption experiments carried out under physiological conditions confirm that the proposed procedure for DCF administration could be achieved.