Device using hydrophilic polymer for delivering drug to biological environment

A Drug delivery device comprising:

• (a) a drug
• (b) a housing having a shape-retaining wall defining an internal space and an opening connecting the space with the exterior of the device, said housing formed of a member selected from the group consisting of a fluid permeable and microporous polymers;
• (c) a container in the housing, the container consisting essentially of a collapsible wall surrounding a reservoir for storing the drug and a passageway that projects through the opening for delivering drug from the container to the exterior of the device, said container formed of a material selected from the group consisting of natural rubber, gutta, percha, cyclised rubber, synthetic rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, chloroprene rubber and ethylene-propylene rubber;
• (d) a laminate in the housing, the laminate surrounding the container and comprising a lamina of an absorbent material and a lamina of a swellable hydrophilic polymer, said laminate capable of imbibing fluid into the housing through the polymer thereby causing the laminate to expand and exert pressure on the container which collapses said container and concomitantly pumps drug through the passageway from the device at a controlled rate over a prolonged period of time.