Modulated release from drug delivery devices.

Modulated drug release devices are devices that are capable of adjusting drug output to meet a physiological need. Such devices can be broadly grouped as externally modulated and self-modulated. In the former case, an externally generated signal is applied to the device, which then adjusts drug output in response to the intensity of the signal. In the latter case, the changes in drug release are caused by changes in the environment surrounding the polymer and no external signal is necessary. Because of the real need for an improved treatment of diabetes, a significant portion of the research currently under way deals with the modulated release of insulin.