Evaluation of carboxymethyl chitin as a drug carrier - Effect of the deacetylation degree on the biodegradation and biodisposition characteristics inmice

6-O-Carboxymethyl chitin (carboxymethyl chitin) was examined on the effect of the deacetylation degree on the biodegradability a,td biodisposition cha racteristics. The deacetylation degree of carboxymethyl chitin was controll ed by changing the alkaline treatment time, when the carboxymethyl chitin w ith the x percent deacetylation degree was named CM-DAx. CM-DA11, CM-DA18 a nd CM-DA30 were used in this study. They were labelled using fluorescein is othiocyanate (FITC), and named FTC/CM-DA11, FTC/CM-DA18 and FTC/CM-DA30, re spectively, and used for-the in vivo examination. The less biodegradability of carboxymethyl chitin was observed as the deacetylation degree increased . When CM-DAx was injected intravenously into mice, the elimination from th e bloodstream and the excretion into urine became slower as the deacetylati on degree increased However, even FTC/CM-DA30 underwent rather fast urinary excretion. CM-DAx- showed a slight distribution in other issues. According ly, the body retention of carboxymethyl chitin may be controlled by changin g the deacetylation degree, but some treatment such as considerable deacety lation or making it solid will be needed for utilizing carboxymethyl chitin as a drug carrier showing long retention in the body.