a drug eluting medical device is provided for implanting into vessels or luminal structures within the body of a patient . the coated medical device , such as a stent , vascular , or synthetic graft comprises a coating consisting of a controlled - release matrix of a bioabsorbable , biocompatible , bioerodible , biodegradable , nontoxic material , such as a poly polymer , and at least one pharmaceutical substance , or bioactive agent incorporated within the matrix or layered within layers of matrix . in particular , the drug eluting medical device when implanted into a patient , delivers the drugs or bioactive agents within the matrix to adjacent tissues in a controlled and desired rate depending on the drug and site of implantation .