Study On Konjac Glucomannan-Xanthan Gum Polysaccharides Mixtures As Drug Delivery Carrier

Konjac Glucomannan (KGM), a water-soluble and high-molecular weight polysaccharide that is the main content of Amorphophallus Konjac plant. Xanthan gum (XG) is known to have a greater drug release retarding property and synergistically enhances gel properties. As the strong synergistic interaction between KGM and XG, the mixture of KGM and XG was employed in extend-release matrix tablets and compression coated colon drug delivery tablets. Cimetidine was used as model drug in the studies. The drug release behavior of tablets was investigated in dissolution studies. Films of polysaccharides mixture were made and the swollen abilities of them were investigated. The diffusion behavior of drug release from the films was studied in the dissolution conditions of different enzyme concentration. The structures and performances of KGM, XG and the mixture of them were investigated by viscosity meter, static laser light scattering (SLS), fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD), X-ray diffraction (XRD) and small-angle X-ray scatter (SAXS). The drug release kinetics model that related enzymatic degradation process and drug release profiles was founded. The preparation process and the drug release behavior of the matrix tablets were researched. It could be found that different ration of KGM and XG may lead different effect to tablet preparation and drug release profile. It was shown that the synergistic interaction between KGM and XG would take effect on the drug diffusion that could retard drug release from tablets effectively. The experimental results demonstrated that the polysaccharides mixture of KGM and XG had a good potential application for controlled drug delivery system.Colon-specific compression coated tablets were prepared with polysaccharides mixtures as coat. 0.220U·ml-1β-mannanase solution in mimic colon media was determined by comparing the hydrolytic ability of mimic colon solution with that of 4%w/v rat cecal content media. It was shown that the synergistic interaction between KGM and XG and the hydrolysis of coat material byβ-mannanase. The experimental results demonstrated that the polysaccharides mixture of KGM and XG as compression coat had a good potential application for colon drug delivery system.It was found that the different diffusion profiles of drug were inducted by different proportion of KGM and XG in the polysaccharides mixture films. The results shown that the enzyme in the dissolution media led accelerate action to drug release.The viscosity of the polysaccharides mixture solutions were measured under different shear rates. The molecular weights of the polysaccharides were measured by static laser light scattering. The synergistic interactions between polysaccharides were observed by fourier transform infrared spectroscopy (FT-IR) and circular dichroism (CD). X-ray diffraction (XRD) and small-angle X-ray scatter (SAXS) were utilized to characterize the structures of the polysaccharides and the mixtures. Morphologies of them were scanned by atomic force microscopy (AFM) and the image of the polysaccharides shown that three-dimension networks were formed in the mixtures with some certain rules.According the drug release behavior from films of polysaccharides mixtures in different enzymatic activity solutions, the drug release kinetics model was founded based on the Michaelis-Menten equation. The model shows a good correlation with the experimental results, which could justify considering it for other biodegradable release system.