Intratumor treatment of C3H mouse mammary carcinoma with 5-fluorouracil adsorbed on activated charcoal particles.

A dosage form comprising 5-fluorouracil (5-FU, 25 mg/ml) adsorbed on a suspension of micronized charcoal (100 mg/ml) 2-5 microns in diameter, adsorbing 5-FU in aqueous solution was studied for intratumor treatment of mammary carcinoma in animal experiments. An in vitro desorption method is described to determine the amount of 5-FU adsorbed on activated charcoal particles which would be released once the drug concentration decreased around the charcoal. In vivo results indicate that an intratumor injection of 5-FU adsorbed on activated charcoal particles is a highly effective method for achieving tumor regression without increasing toxicity.