Enhanced anti-cancer efficacy on lymph node metastasis using peplomycin adsorbed on small activated carbon particles

A new dosage form (PEP-CH) of peplomycin was tested for therapeutic efficacy against lymph node metastasis in mice. PEP-CH is a suspension comprising 4 mg/ml of activated carbon, 2 mg/ml of peplomycin and 1.6 mg/ml of polyvinylpyrrolidone in saline. Mice were subcutaneously inoculated with 3 x 10(5) MH134 tumor cells into the left hind paw. Drugs were given on day 10 when cancer had been metastasized in the left popliteal lymph node. Mice were killed on day 17 and the left popliteal lymph node and the left deep inguinal lymph node were extirpated. Since the degree of the metastatic lesion and the lymph node weight correlated with a statistically high probability with each other, the degree of metastatic lesion was evaluated through comparison of lymph node weight. The left popliteal lymph node and the deep inguinal lymph node were 10.5 mg and 4.5 mg in average weight, respectively, in the mice given PEP-CH containing 0.1 mg of peplomycin subcutaneously into the left hind foot-pad. The weights were significantly smaller than those in the mice given an identical dose of peplomycin aqueous solution subcutaneously into the left hind foot-pad or intraperitoneally.