Abstract of the Disclosure Implantable drug delivery devices include a housing defining a reservoir a first unit within the reservoir and a second unit within the reservoir. The first unit contains a drug and the second unit contains a functional agent that facilitates release of the drug. Intravesical drug delivery devices include a housing portion containing a drug formulation and a housing portion containing an excipient and are configured to release the drug according to a first release profile and the excipient according to a second release profile. Methods include inserting any of these devices into a patient and releasing drug from the device.
