Toxicity and pathological effects of a new dosage form of mitomycin C for carcinomatous peritonitis

A new dosage form (MMC-CH) of mitomycin C (in a suspension of activated carbon adsorbing mitomycin C in saline), designed for intracavitary use in carcinomatous peritonitis, was studied for its toxicity and pathological effects in rats. The LD50 values determined with the Litchfield-Wilcoxon's method in three types of MMC-CH were 7.6 (100 micrograms/ml MMC and 0.5 mg/ml activated carbon in saline), 16.5 (100 micrograms/ml MMC and 0.75 mg/ml activated carbon in saline), and more than 25 mg/kg (100 micrograms/ml MMC and 1 mg/ml activated carbon in saline), while in mitomycin C solution the value was 3.05 mg/kg. The lethal toxicity decreased with the change of dosage form. Studies on survival, symptoms of intoxication and macroscopic and microscopic examinations of autopsied animals revealed that there was no evidence of any additional side effects produced by the change of dosage form.