| 摘要 |
<p>A controlled release device for delivering an active material to a patient after a predetermined time interval comprises a male hydrogel plug (6) engaged within a neck portion (4) of a female body (2). When the device is exposed to an aqueous medium, the hydrogel plug swells and disengages. The reproducibility of the disengagement time is improved by employing a plug whose cross-sectional area exceeds the internal cross-sectional area of the neck portion. Generally the ratio of cross-sectional areas is about 1.04 to one.</p> |
