Blood is known to be the main transport route of most drugs because of the much greater flow rate of the blood stream than that of the lymphatics. The lymphatic transport of drugs, however, is noteworthy, because the lymphatic route is important for many chemicals ; namely as an essential route for nutrient lipids and a route to avoid the first pass effect of the liver for drugs which are absorbed from the gastrointestinal tract and the necessity to deliver anticancer agents into the lymphatic system of patients suffering from the cancer. It follows that in tumor metastasis, the lymphatic pathway is a major route and a lymphotropic transport of antitumor drugs is to be of great significance for cancer chemotherapy. In this paper, fundamentals of lymphatic transport of chemicals, development of lymphotropic drug delivery systems and their application to therapy are described.
