The proposed research represents an attempt to develop and evaluate carriers that will impart some degree of tissue specificity to the distribution pattern of anticancer drugs. Various anticaner drugs are to be attached to or encapsulated within macromolecular drug carriers, and tested for their ability to localize within phagocytically active cells. In vitro studies will examine incorporation of drugs, and the physical-chemical stability of the formulations. Radiotracer techniques will be employed to quantify uptake of both drug and carrier after incubation with cultured tumor cells. Cytotoxicity will be determined using adequate controls. The rate of removal of drug-carrier complex from the plasma of mice will then be determined along with their tissue distribution. Finally, the effectiveness of the formulations against several experimental cancers such as Sarcoma-180 and leukemia L1210, will be determined in mice.