Transporters and drug delivery system by using the same

摘要

An object of the present invention is to prepare substances which are excellent in delivery and enable drugs to be retained in a body effectively over a long period and to construct a drug delivery system using the substances. When the delivering substance which is obtained by reacting polyalkylene glycol or a reactive derivative thereof, a phospholipid and a drug with each other to form covalent bonds is administered systemically or topically, the substance is retained at a target site in a body for a long period, thereby making it possible to sustain drug efficacy over a long period by a single administration.