Preparation And Application Of N-Succinyl Chitosan Immobilized With β-Cyclodextrin(CDS)

Chitosan and cyclodextrin are well-known naturally occurring polysaccharides which are widely used in biomedical and environmental engineering areas. Chitosan and its derivatives possess excellent bioactivity and adsorption ability. Cyclodextin are cyclic oligosaccharides with a lipophilic central cavity and a hydrophilic outer surface, able to form inclusion complexes with lipophilic molecules. Therefore, grafting CD molecules into chitosan may lead to a molecular carrier exhibiting promising properties because of the cumulative effects of both.In this paper, a novel approach to prepare N-succinyl chitosan immobilized withβ-cyclodextrin(CDS)had been set up. The experimental results of synthesis indicated that CDS can be obtained using epichlorohydrin as crosslinking agent with a higher yield under mild conditions, and the reaction was affected by the concentration of NaOH, the amount of crosslinking agent, the reactive temperature and the weight ration ofβ-CD/SCS. The CDS was characterized by FTIR and element analysis. The apparent amounts ofβ-CD content in CDS were determined by ultraviolet spectroscopy and element analysis respectively. According to this novel approach, apparent amounts ofβ-CD and SCS content in CDS could be controlled and higher.The adsorption experiments of CDS for 2, 4-dinitrophenol had been carried out. The experimental results showed the optimal adsorption conditions as follows: 30℃, 60min, pH3.6. The adsorption capacity of CDS to 2, 4-dinitrophenol was increased with enlarging the concentration of 2, 4-dinitrophenol. The adsorption rate of 2, 4-dinitrophenol would reach to 100%, while 0.1g CDS and 10 mL of 1.5×10-2mg/mL 2, 4-dinitrophenol solution was used. The experimental results showed that the adsorption capacity of CDS to 2, 4-dinitrophenol was much higher than that of ECS, ECD and CS. This may be owing to the cumulative effects of cyclodextrins's complexes ability and chitosan's adsorption ability.To understand the molecular interaction mechanism of inclusion complex betweenβ-CD and the medicine, the supramolecular interaction between parent ?β-CD and ketoprofen in aqueous solutions was studied by UV spectrophotometer. The solid inclusion complexes ofβ-CD/ ketoprofen were also prepared, and the results of IR, DSC, TG and the power X-ray diffraction data indicated that novel crystalline structure for inclusion complex exists. Using ketoprofen (KP) as model drug, the release behavior of ketoprofen from CDS in simulated gastric juice and intestinal liquid had been carried out. The results indicated that the drug release equilibrium was reached and the equilibrium rates of KP release were closed to 100% after 40h in simulated gastric juice and 10h in intestinal liquid. To get the mechanisms of drug release of CDS, the drug release behavior in different polymer matrixes (ECD and ECS) was studied as well. It seemed that the release of KP obeyed a swelling-controlled release mechanism, especially at the initial period of release, and the release was most probably followed by a diffusion-controlled mechanism after the initial period, in which the swelling equilibrium was achieved. The pH-response property of the drug-loaded CDS was valuable for application.