a self - powered device for dispensing a medicament is disclosed . the device comprises a rigid housing defining an internal space , a container in the housing formed of a stretched polymer and having a passage - way connecting the container with the exterior of the device , a medicament in the container , and and expandable laminate surrounding the container positioned between the interior of the housing and the exterior of the container . the laminate comprises a lamina of an absorbent material laminated to a lamina of a swellable , hydrophilic polymer . in operation , when the device is in a biological fluid environment , fluid therefrom is imbibed by the laminate into the housing , causing the laminate to expand and exert pressure on the container , thereby shrinking the container to an unstretched state , which decreases its volume and concomitantly pumps medicament through the passageway at a controlled rate over time .