this invention is related to the use of polyurethane based polymer as a drug delivery device to deliver biologically active compounds at a constant rate for an extended period of time and methods of manufactures thereof . the device is very biocompatible and biostable , and is useful as an implant in patients for the delivery of appropriate bioactive substances to tissues or organs . the drug delivery device for releasing one or more drugs at controlled rates for an extended period of time to produce local or systemic pharmacological effects comprises : 1 . a reservoir , said reservoir comprising ; 2 . at least one active ingredient ; and , optionally , 3 . at least one pharmaceutically acceptable carrier ; a polyurethane based polymer completely surrounding the reservoir .