Preparation And Drug Release Property Of Chitosan Carrier Drug Microspheres

Chitosan has biological adhesion and slow-release potential, which can be widelyused in local drug delivery. Preparation of carboxymethyl chitosan carrier drugmicrosphere can be better into the tumor cells and reduce the patients with difficultresistance characteristics of the drug. Under the additional magnetic orientation system, asdirectional carrier drug delivery, magnetic chitosan microspheres release to the specificlesion site. After remove of magnetic field, magnetic microspheres can be safely out of thebody. Magnetic carboxymethyl chitosan microspheres not only increase its target, but alsoenhance the good biological compatibility, thus the side effects of drugs are reduced on thehuman body normal tissue.First, ferriferrous oxide is prepared by coprecipitation methods，and carboxymethylchitosan is prepared by alkaline carboxymethylation. Then chitosan microballoonspheresare prepared by crosslinking-emulsion methods. At last, drug-releasing properties ofmicroballoons are measured by dialysis at different pH values and different temperature.The result can be discoverd from experimental data that drug loading properties ofarboxymethyl chitosan microspheres and magnetic carboxymethyl chitosan microspheresare better. So they are more suitable for clinic treatment.The performance of chitosan microspheres is better than anticarcinogen of5-fluorouracil in the drug-releasing performance experiment. Experimental results show thatdrug carrying microspheres of chitosan will have a good performance at drug-releasingwhen pH is5.2, which accords with the pH value of intestinal juice; drug carryingmicrospheres of chitosan can reach maximum release when temperature is approximately35℃to40℃, which conforms to the temperature of man. So the conclusion can be madethat drug carrying microspheres of chitosan are suitable for intestinal targeted drugdelivery carrier material.