Electron Irradiation Crosslinking Process Of Chitosan Gel And Its Stability Study

Along with the development plan for northern medicine proposed, traditional Chinese medicine has been attached more and more attention. While the pharmaceutical excipients as an important part of pharmaceutical preparations, with the rapid development of biotechnology, genetic engineering and materials science, begins to increasingly affect the use of drugs. The same drug used in different materials can be made into different dosage forms, thus changing the administration route, drug onset time, efficacy duration time, and even effect change dramatically. Therefore the researches on pharmaceutical excipients with safe, nontoxic, excellent sustained and controlled release properties, good biocompatibility and biodegradability are of great significance.In this paper, dilute lactic acid solutions with different concentrations was taken as a dispersing system, and chitosan sols of different concentrations were configured, by means of electron irradiation, to prepare a pH-sensitive chitosan hydrogel. Combined with structural stability of hydrogel, the following conclusions were obtained:The crosslinking reaction of chitosan sol occurred under electron beam irradiation, and chitosan gel was obtained. Compared before and after irradiation, the appearance of chitosan gel was darker, showing interconnected honeycomb holes, with the hole diameter ranged between 50-500?m.The TG temperature of irradiated chitosan improved significantly. The optimal irradiation process: chitosan concentration was at 50wt%, the lactic acid concentration was at 2wt%, and irradiation dose at100 kGy.Before and after the irradiation treatment, the hydrophilia change of chitosan gel was not very clear, and the infrared characteristic absorption peak position of Chitosan remained the same, indicating that after irradiation chitosan structure did not change obviously. The crosslinking only consumed less hydrophilic groups.Chitosan gel showed a good pH sensitivity. And its saturated swelling ratio gradually reduced with pH value becoming larger. At pH value close to about 7, it reached around a lower swelling ratio, and then hardly changed.In the paper, chitosan hydrogel was obtained by electron beam irradiation, with no crosslinking agent, high product purity and pH-sensitive, can be used as a drug carrier to be applied in pharmaceutical field of polymer materials. Due to its simple preparation method, there will be strong competitive advantages and broad application prospects.