| 摘要 |
The invention provides a long-term dispensing device comprising a first agent delivery means for short-term and continuous delivery of agent, retained together with a second agent delivery means capable of long-term and continuous delivery of agent. The combination of first and second agent delivery means provides a device in which a substantially constant dose of beneficial agent is delivered to the environment of use over time. A rapid delivery of beneficial agent is followed by continuous and prolonged delivery of agent. In a preferred embodiment the device includes (1) a short term delivery means for rapid and continuous delivery of agent to the environment of use; and (2) a long-term delivery means comprising a semipermeable wall which surrounds and defines an internal lumen; a means in the lumen for expanding and occupying an increased volume of the lumen; a beneficial agent in the lumen that provides a dispensable formulation to the environment of use; and a means in the device for delivery of the beneficial agent to the environment of use over time. |
