A new dosage formulation (ACR-CH), composed of aclarubicin (ACR) bound to fine activated carbon particles, has been developed for the treatment of lymph node metastases in breast cancer. ACR-CH is designed to (a) adsorb a great amount of aclarubicin and desorb in a free state; (b) distribute a greater amount of ACR for a longer period of time selectively to the regional lymph nodes; (c) be decreased in the systemic toxicity; and (d) enhance its therapeutic effect on lymph node metastases. In this clinical trial in 20 patients with breast cancer, ACR-CH was injected intra- and peritumorally just before operation for breast cancer, and we examined the extent of blackened nodes produced by ACR-CH. ACR-CH blackened about 70% of the axillary lymph nodes with cancer metastasis as well as the nodes without metastasis. In conclusion, ACR-CH will be useful for dissection of lymph nodes by visualizing the nodes during operation for breast cancer.