injected into the tongue black light at the strength of 2500 u03bcw cm 2 was immediately irradiated to the tongue for 30 minutes after the injection in one group 14 rats no uv light treatment was given to another group both groups were fed for 9 days in a normal manner to compare changes in body weight of surviving mice until day 9 the results are shown in fig2 and the following table when uv treatment was not conducted 43 of the rats died since tumors were formed in the tongue of the rats due to an action of adriamycin bonded to the particle and the rats were unable to ingest feeds their body weights decreased until day 3 in the group receiving uv irradiation on the contrary clear alleviation of inflammation was observed in a comparison conducted 5 hours after uv irradiation and only a trace of tumors remained 1 day after irradiation it was thus shown that cytotoxicity of adriamycin was completely eliminated by uv irradiation of about 30 in addition the body weight scarcely decreased in the group receiving uv irradiation and it was thus indicated that this treatment was very effective for reducing adverse drug reactions study of antitumor effect of.