초록 ▼

An implantable osmotically driven syringe is disclosed which can be used to deliver a beneficial agent, such as a drug, at a predetermined rate over an extended period of time. A movable piston divides the syringe into a beneficial agent-containing compartment and a driving compartment. The piston i

An implantable osmotically driven syringe is disclosed which can be used to deliver a beneficial agent, such as a drug, at a predetermined rate over an extended period of time. A movable piston divides the syringe into a beneficial agent-containing compartment and a driving compartment. The piston is movable into a position wherein the driving compartment has a volume of essentially zero. The syringe is driven by an osmotic engine which has a shaped wall surrounding, and in contact with, an osmotic solute. The wall is comprised of a semipermeable and/or microporous material which is permeable to the external fluid (e.g., water) but is impermeable to the solute. The engine also has a passageway forming a fluid flow path between the osmotic solute and the driving compartment. A portion of the wall is exposed to a fluid-containing external environment. At least about 30% of the wall which contacts the solute also is exposed to the fluid in the external environment. In operation, water from the external environment is imbided through the semipermeable wall forming a solution of the solvent in the osmotic engine. As fresh incoming fluid from the external environment is imbided by the engine, the solution is pumped through the passageway into the driving compartment. The pumping action drives the piston which causes the beneficial agent to be delivered by the syringe.

대표청구항 ▼

An osmotically driven dispensing device for delivering a beneficial agent to an environment of use, the device comprising: a) a syringe having a chamber with a movable piston therein, the piston dividing the chamber into a beneficial agent-containing compartment and a driving compartment, the piston

An osmotically driven dispensing device for delivering a beneficial agent to an environment of use, the device comprising: a) a syringe having a chamber with a movable piston therein, the piston dividing the chamber into a beneficial agent-containing compartment and a driving compartment, the piston being movable into a position wherein the piston occupies substantially all of the drive compartment; b) an osmotic engine attached to the syringe adjacent the driving compartment, the engine comprising a shaped wall surrounding, and in contact with, an osmotic solute, the wall having an external surface exposed to a fluid in an external environment, and a passageway providing a fluid flow path between the osmotic solute and the driving compartment, the wall being comprised of a material that is permeable to the external fluid and having a sufficient degree of impermeability to the solute to generate an osmotic pressure differential across the wall when exposed to the external fluid, at least 30% of the wall which is in contact with the osmotic solute also being exposed to the external environment; wherein in operation, the external fluid is imbibed through the wall into the osmotic engine to form a solution of the osmotic solute, the solution being pumped through the passageway into the driving compartment as fresh fluid is imbibed through the wall, thereby exerting pressure on the piston and forcing the piston to move within the syringe chamber and deliver the beneficial agent from the beneficial agent-containing compartment to the environment of use.