A method to administer a drug locally to a subject in which biodegradable dosage forms that contain the drug are implanted at a localized site beneath the skin of the subject whereupon the dosage forms release the drug over a desired period of time at a substantially continuous rate. Glyceryl monostearate based compositions that accomplish the method are also provided. Compositions are further provided that affect the release profile or release duration of drugs that are released from the compositions, as are methods that employ these varying release profiles to provide implantable dosage forms that release drugs at a prescribed rate over a prescribed period of time. The compositions are particularly well adapted to implantable dosage forms because they biodegrade quickly to an acceptable level after delivering the drug.