Physical changes of chitin and chitosan in canine gastrointestinal tract

Abstract

Physical changes of chitin and chitosan were evaluated in canine gastrointestinal tract. Chitin and chitosan were packed into nylon bags (3×1 cm 2, 45 μm mesh) and administered orally, and then the bags were recovered from the feces. Chitosan bags were also inserted surgically into the jejunum and colon. The changes in the weight of the bags were evaluated. Chitosan was decreased to <10% of its original weight and had formed a film, while chitin did not undergo any change in shape or weight. The loss of chitosan was about 40% and the weight loss of chitosan was observed in the colon routes. The weight loss of chitosan in the colon was observed in the presence of colonic contents. An in vitro study was also performed to investigate the physical change of chitosan after treatment with artificial gastric and intestine juices. The in vitro study showed that chitosan became a gel in artificial gastric juice and its weight decreased by 15%, but there were no such physical changes when it was placed in artificial intestinal juice. The present study showed that chitin did not undergo any changes in weight and shape in the gastrointestinal tract, whereas chitosan did. In addition, chitosan was found to be affected in the stomach and large intestine, but not in the small intestine.