A novel approach to loco-regional cancer chemotherapy with a chitosan-CDDP solution

The authors applied 70% deacetylated chitin (DAC 70, chitosan) as a vehicle of cis-platinum (CDDP) to achieve loco-regional cancer chemotherapy, in an attempt to hold the drug in the target region with a locally sustained release. The DAC-70 powder was dissolved in a 0.1 M HCI solution into where CDDP solution and glycerol phosphate solution were added. The resulting product, DAC-70/CDDP became a muco-adhesive solution. The adhesiveness between the solution and human colonic mucosa was measured ex vivo by our own method, and a release profile of the CDDP was examined in vitro using an atomic absorption method. The adhesive force was stronger at 37 degrees C than that of at 25 degrees C. Ten percent of the CDDP was gradually delivered for 6 hours, while the release was maintained at the same levels for the following 72 hours. The release rate increased by 10-20% when lysozyme was added in the incubation systems. However, the release profile of the drug showed no remarkable changes. The DAC-70/CDDP solution provided a favorable adhesiveness with human colonic mucosa, while in situ degradability of the solution should be improved further more.