Adsorption of cefotaxime sodium salt on polymer coated ion exchange resin microparticles: Kinetics, equilibrium and thermodynamic studies

Microparticles with complex architectures based on the polyelectrolyte complexes between an acrylic ion exchange resin and two polysaccharides: gellan and xanthan gum were prepared and used for the adsorption of antibiotic in order to obtain a new drug delivery systems. Batch adsorption studies have been carried out to determine the effect of the contact time, temperature and the initial concentration of drug solution on the adsorption behavior. The Langmuir, Freundlich, Temkin and Dubinin–Radushkevich adsorption isotherms were used to model this behavior. The kinetics were fitted with the pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models. The best results were achieved with pseudo-second order kinetic model. The thermodynamic parameters (ΔG, ΔH, ΔS) were also calculated and the values indicate that the adsorption process was endothermic and spontaneous. The results showed that the microparticles with complex structures have a higher adsorption capacity, making it suitable for use in drug delivery systems.