Osmotically driven syringe
First Claim
1. An osmotic engine comprising:
- (a) a shaped wall defining a compartment, the compartment containing an osmotically effective solute, at least a portion of the wall being comprised of a material that is permeable to and hydrated by an external fluid and having a sufficient degree of impermeability to the solute to generate an osmotic pressure differential across the wall when the wall is exposed to an external fluid, the wall also having a passageway therethrough connecting the compartment with an exterior environment; and
(b) a rigid non-dissolving wall support for supporting the wall and maintaining the wall shape, the rigid support having at least one open fluid flow path extending from the semipermeable wall portion toward the passageway through the wall,wherein in operation, a solution of the solute is delivered from the engine by the external fluid being imbibed through the semipermeable wall portion into the osmotic solute-containing compartment to form a solution containing the osmotic solute, the solution being pumped along the open fluid flow path and through the wall passageway to the exterior environment.
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Accused Products
Abstract
An improved osmotic engine is disclosed. The osmotic engine is adapted to be used with an osmotically driven syringe which can be used to deliver a beneficial agent, such as a drug, at a pre-determined rate over an extended period of time. The osmotic engine has an exterior wall defining a compartment which contains an osmotic solute. The wall comprises a thin permeable and/or microporous material which is permeable to an external fluid such as water but is impermeable to the solute. The wall also has a delivery orifice drilled therethrough. A rigid non-dissolving ring-shaped wall support is provided for maintaining the shape of the engine during use. The wall support also provides a fluid flow path extending from the semipermeable wall portion toward the delivery orifice.
120 Citations
31 Claims
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1. An osmotic engine comprising:
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(a) a shaped wall defining a compartment, the compartment containing an osmotically effective solute, at least a portion of the wall being comprised of a material that is permeable to and hydrated by an external fluid and having a sufficient degree of impermeability to the solute to generate an osmotic pressure differential across the wall when the wall is exposed to an external fluid, the wall also having a passageway therethrough connecting the compartment with an exterior environment; and (b) a rigid non-dissolving wall support for supporting the wall and maintaining the wall shape, the rigid support having at least one open fluid flow path extending from the semipermeable wall portion toward the passageway through the wall, wherein in operation, a solution of the solute is delivered from the engine by the external fluid being imbibed through the semipermeable wall portion into the osmotic solute-containing compartment to form a solution containing the osmotic solute, the solution being pumped along the open fluid flow path and through the wall passageway to the exterior environment. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An osmotically driven dispensing device for delivering a beneficial agent to an environment of use, the device comprising:
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(a) a syringe having a movable piston, the piston dividing the syringe into a beneficial agent compartment and a driving compartment; (b) a fluid reservoir; and (c) an osmotic engine intermediate said reservoir and said driving compartment, said osmotic engine including; (i) a shaped wall defining a compartment, the compartment containing an osmotically effective solute, at least a portion of the wall being comprised of a material that is permeable to and hydrated by an external fluid and having a sufficient degree of impermeability to the solute to generate an osmotic pressure differential across the wall when the wall is exposed to the fluid reservoir, the wall also having a passageway therethrough connecting the osmotic solute-containing compartment with the driving compartment; (ii) a rigid non-dissolving wall support for supporting the wall and maintaining the wall shape, the rigid support having at least one open fluid flow path extending from the semipermeable wall portion toward the passageway through the wall; wherein in operation, a beneficial agent is delivered from the device by fluid from the reservoir being imbibed through the semipermeable wall portion into the osmotic solute-containing compartment to form a solution containing the osmotic solute, the solution being pumped along the open fluid flow path and through the wall passageway into the driving compartment, thereby exerting pressure on the piston to deliver the beneficial agent from the beneficial agent compartment to the environment of use. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification