Adsorption and release studies of cefuroxime sodium from acrylic ion exchange resin microparticles coated with gellan

Two types of microparticles based on acrylic ion exchange resin were prepared and used as macromolecular supports for the adsorption of an antibiotic (cefuroxime sodium salt) from aqueous solution. The first type of microparticles was synthesized by aqueous suspension copolymerization of acrylonitrile, ethylacrylate and ethylene glycol dimethacrylate followed by the aminolysis reaction of ternary copolymer with hydrazine hydrate. For the preparation of the second type of microparticles the gellan was selected to cover the surface of acrylic ion exchanger in order to increase the biocompatibility of these systems. Batch adsorption studies regarding the effects of various parameters such as, temperature, contact time, initial concentration of drug, drug:microparticles ratio and pH were studied. To study the adsorption kinetic mechanism, the Lagergren, Ho, Elovich and Weber-Morris particle diffusion models were applied and it was found that the adsorption of the drug could be described by pseudo first order equation (Lagergren model). The calculated values of thermodynamic parameters (ΔG, ΔH, ΔS) showed that the adsorption process was spontaneous and endothermic. The drug release process was found to be controlled by diffusion of drug molecules through polymer networks.