A therapeutic implantable device comprises a biodegradable outer shell, a plurality of spaced biodegradable layers within the outer shell, a first therapeutic mass between the plurality of spaced biodegradable layers and a second therapeutic mass between the plurality of spaced biodegradable layers. The plurality of spaced biodegradable layers are arranged such that the first therapeutic mass is exposed external to the implantable device before exposure of the second therapeutic mass external to the implantable device.
