A newly developed drug delivery system using fine particles of activated charcoal for targeting chemotherapy.

: Targeting chemotherapy to the metastatic lesions of the lymph nodes after surgical removal of the main tumor, a drug delivery system using ultrafine particles of activated charcoal was developed and examined for its ability to adsorb mitomycin C (MMC) and to transport MMC to the lymph system. Satisfactory results were obtained. In animal experiments, serial sampling of thoracic duct lymph by cannulation and serial samplings of peripheral vein blood after injection of MMC-charcoal solution into the subserosal space of the intestinal wall were made to study the pharmacodynamics of the lymph-blood system through analysis of MMC regression curves. Clearance (K) and half-life (t1/2) are calculated from the formula; C(t) = C(t0) X e-kt, and compared with that of MMC-saline. Activated charcoal has a proven ability to transport MMC to the lymphatic system. With activated charcoal, MMC is retained for much longer in the lymph nodes than with saline. Congestion of the lymph system was produced by ligation of the thoracic duct in CH-40, with 25% prolongation of t1/2. In conclusion, these drug delivery systems are suitable for targeting chemotherapy at lymph node metastases, and it is proven that 1500 AA Mitsubishi ultrafine charcoal is a good carrier of drug and a slow drug-release material in the lymphatics. Minimal side effects are expected because of the constant low concentrations in the general circulation.