An orifice-free drug delivery device is provided. In an embodiment, the device includes a body having at least one water-permeable wall bounding a reservoir defined within the body. A drug formulation is disposed within the reservoir. The body has an elastic portion and at least one restraining plug closing off an opening of the body. The opening is in fluid communication with the reservoir, and the restraining plug contacts the elastic portion of the body and controls release of the drug from the device by the transient formation of one or more microchannels between the elastic portion of the body and the at least one restraining plug. The elastic portion may define an opening having an inner diameter, which is exceeded by the outer diameter of the restraining plug by at least 3%.
