抄録
Nine lipophilic la-N-substituted prodrugs of mitomycin C were formulated in lipid dispersion dosage forms and their fundamental antitumor acrivities were evaluated. The prodruge were efficiently incorporated into liposome of O/W emulsion according to their increased lipophilicities, while mitomycin C was hardly entrapped into them. Almost complete incorporation was observed in nonyloxycarbonyl and cholesteryloxycarbonyl mitomycin C which showed partition coefficients over 800 in chloroform/water system. The release rate from these dosage forms determined by a dynamic dialysis method decreased with an increase in the partition coefficients of the derivatives. All prodrugs entrapped in liposome of O/W emulsion showed significant antitumor acrivities against L1210 leulemia in i.p.-i.p. system except for cholesteryloxycarbonyl mitomycin C. In spite of comsiderable antitumor activities showen in the forms of liposome and emulsion, saline suspension of nonyloxycarbonyl mitonycin C failed to exhibir any actibity because of its poor aqueous solubility. These results suggested the utility of the combining delivery system of lipophilic prodrug with physical device such as liposome and O/W emulsion.
