THERAPEUTIC EFFECT OF RETICULOENDOTHELIAL SYSTEM (RES)-AVOIDING LIPOSOMES CONTAINING A PHOSPHOLIPID ANALOG OF 5-FLUOROURACIL, DIPALMITOYLPHOSPHATIDYLFLUOROURIDINE, IN METH-A SARCOMA-BEARING MICE

Reticuloendothelial system (RES)-avoiding liposomes are known to accum ulate in tumor tissues due to passive targeting. Dipalmitoylphosphatid ylfluorouridine (DPPF), a potent antitumor agent readily incorporated into the lipid bilayer, was embedded in RES-avoiding liposomes modifie d with a uronic acid derivative, palmityl-D-glucuronide (PGlcUA). The therapeutic effect of DPPF in PGlcUA-liposomes was examined in tumor-b earing mice. Free or liposomal DPPF was injected intravenously into BA LB/c mice bearing subcutaneously implanted Meth A sarcomas. The RES-av oiding liposomal formulation using PGlcUA was effective in reducing tu mors, and prolonging survival time compared with free DPPF and also DP PF in conventional liposomes. Therefore, PGlcUA-liposomes might be of practical use as drug carriers for anticancer agents, especially their derivatives for embedding in liposomal membranes.