Device for sustained release of active substance.

摘要

A device for the sustained release of active substance comprises a wall (1) defining a cavity for the reception of active substance, the wall being of impermeable material and having one or more ports (2) therethrough. Sections of hydrogel material (3) are within the cavity, the hydrogel, in use, being swollen to cover the ports (2) in the cavity wall. Active ingredient is released from the container only through the hydrogel (3) covering the ports (2). In this way sustained and controlled release of the active substance from the device is obtained.