| 摘要 |
An osmotic system is disclosed for delivering an agent. The system comprises a semipermeable wall surrounding a compartment. The compartment contains a layer of a compound that is insoluble in an exterior fluid, and juxtaposed with a layer of an agent that is soluble in the fluid. A passageway through the wall connects the exterior of the system with the interface between the wall and the insoluble compound. In operation, agent is delivered from the system, by the agent imbibing fluid into the compartment to form a saturated solution of agent, that is moved along the interface between the wall and the insoluble compound towards the passageway. The saturated solution is moved continuously by the corresponding imbibition of fluid, and as the solution moves along the interface it imbibs fluid, is diluted and delivered below a saturated concentration to the exterior of the system. The invention also concerns a two layered structure comprising a layer of an aqueous insoluble compound and a layer of an aqueous soluble compound.
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