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Abstract:Chitosan powder irradiated by electron beam at different doses, up to 250 kGy, was used to prepare membranes for drug release applications. The irradiation effect on the molecular weight of powder chitosan, the characteristics of the prepared membranes, and their transport of sulfamerazine sodium salt (SULF) were investigated. The effect of the addition of glutaraldehyde (GLA) as a crosslinking agent in the chitosan solution used for the preparation of the membranes was also studied. A decrease in the chitosan molecular weight with the increase in the irradiation dose was observed, while the membranes prepared with the irradiated chitosan at higher dose exhibited lower swelling. However, an opposite behavior was detected when the membranes were prepared with GLA-crosslinked chitosan. A GLA crosslinking agent reduced the crystallinity of the chitosan membranes and the swelling, whereas the water contact angle and SULF transport increased with the increase in the irradiation dose.

Chitosan (CS) composite membranes were prepared using different biocompatible metal oxide nanoparticles (NPs): titanium dioxide (TiO2); iron oxide (Fe3O4); and aluminum oxide (Al2O3). For each nanoparticle, the CS-based composite membranes were prepared with two NPs contents in the CS solution, high (H) and low (L) NPs concentrations. To establish both concentrations, the NPs saturation point in the CS polymeric matrix was determined. The influence of NP concentrations on the physicochemical properties of the CS films was assessed. The prepared CS membranes were characterized with different techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and zeta potential. It was found that the addition of NPs in the CS matrix improved both swelling and mechanical properties. Nanocomposite CS membranes could be prepared using Al2O3 NPs. Swelling experiments revealed different pH-sensitive mechanisms, which might be beneficial in biomedical applications since solute permeation through CS-based composite membranes could be controlled by adjusting environmental conditions. When aspirin transport (ASA) through the prepared membranes was carried out in different release media, SGF (simulating gastric fluid) and SIF (simulating intestinal fluid without enzymes), it was observed that the Fickian diffusion coefficient (D) was conditioned by the pH of the release solution. In SGIT (simulating gastrointestinal transit) medium, a transition time (ttrans) was detected due to the shrinkage of the CS polymeric chains, and the drug release depended not only on the Fickian’s diffusion but also on the shrinkage of the biopolymer, obeying Peppas and Sahlin equation.