Osmotic device having microporous reservoir

An osmotic device for continuously dispensing an active agent to an environment of use, said device comprising:

• a. a shaped wall formed of a semipermeable material that is permeable to the passage of an external fluid and substantially impermeable to the passage of an active agent, said wall surrounding in part;
• b. a compartment formed of a microporous material and having at least one micropore that communicates with the compartment and the exterior of the device, said compartment containing an active agent having limited solubility in the external fluid and an osmotically effective compound which exhibits an osmotic pressure gradient across the wall against the fluid;
• c. a passageway for dispensing agent from the device, said passageway consisting of at least one micropore that communicates with the exterior of the device;
• and
• d. wherein in operation with the device in the environment of use, external fluid is imbibed through the wall into the compartment in a tendency towards osmotic equilibrium at a rate controlled by the permeability of the wall and the osmotic pressure gradient across the wall thereby continuously dissolving the compound, which as a mixture with the agent, is dispensed through the passageway at a controlled rate for a prolonged period of time.

An osmotic device for the continuous dispensing of an active agent to an environment of use, said device comprising:

• a. a shaped wall formed of a material that is permeable to the passage of an external fluid in the environment of use and substantially impermeable to the passage of an active agent with the wall surrounding;
• b. a reservoir formed of a material having a plurality of micropores, said reservoir providing support for the wall and containing an active agent that is soluble in the external fluid and exhibits an osmotic pressure gradient across the wall against the fluid;
• c. a passageway for dispensing agent from the device, said passageway consisting of at least one micropore that communicates with the reservoir and the exterior of the device;
• and,
• d. wherein in operation with the device in the environment of use, external fluid is imbibed through the wall into the reservoir at a rate determined by the permeability of the wall and the osmotic pressure gradient across the wall, thereby dissolving the agent which is dispensed from the reservoir through the passageway to the exterior of the device at a controlled and continuous rate over time.

An ocular osmotic device for the continuous and prolonged administration of an ophthalmic drug, said device comprising:

• a. an ophthalmic drug that exhibits an osmotic pressure gradient against eye fluid;
• b. a shaped wall formed of a semipermeable material that maintains its integrity during the dispensing period and which material is permeable to the passage of eye fluid and substantially impermeable to the passage of drug, the wall surrounding in part;
• c. a reservoir formed of a microporous material with the reservoir containing the drug;
• d. a passageway for dispensing the drug from the device, said pasageway consisting of at least one micropore that communicates with the reservoir and the exterior of the device;
• and
• e. wherein in operation with the device in the environment of use, eye fluid is continuously imbibed through the wall into the reservoir in a tendency towards osmotic equilibrium at a rate determined by the permeability of the wall and the osmotic pressure gradient across the wall, thereby dissolving the drug which is dispensed from the reservoir through the microporous passageway to the environment at a controlled rate over a prolonged period of time.

An oral, osmotic device for the controlled and continuous dispensing of a unit dosage amount of drug to the gastrointestinal tract, said device comprising:

• a. a shaped wall formed of a semipermeable material that is permeable to the passage of an external gastrointestinal fluid and is substantially impermeable to drug, said wall having an opening and surrounding;
• b. a compartment formed of microporous material and containing a unit dosage amount of drug that is soluble in the fluid and exhibits an osmotic pressure gradient across the wall against the fluid when the device is in the environment of use;
• c. a passageway for dispensing the drug, said passageway consisting of at least one micropore that communicates with the opening in the wall and the exterior of the device;
• and
• d. wherein in operation with the device in the environment of use, external fluid is imbibed through the wall into the compartment in a tendency towards osmotic equilibrium at a rate controlled by the permeability of the wall and the osmotic pressure gradient across the wall producing a solution that is dispensed through the passageway from the device at a controlled and continuous rate over a prolonged period of time.

A method for continuously administering an active agent at a controlled rate to the gastrointestinal tract of a warm blooded animal comprising:

• A. admitting into the gastrointestinal tract an osmotic device shaped and sized for oral administration with the device comprising;
• 1. a wall formed of a pharmaceutically acceptable semipermeable material that is permeable to the passage of gastrointestinal fluid and substantially impermeable to the passage of an active agent, said wall having an opening and surrounding;
• 2. a compartment formed of a microporous material and containing a unit dosage amount of active agent that is soluble in the fluid and exhibits an osmotic pressure gradient across the wall against the fluid;
• 3. a passageway for dispensing the active agent, said passageway consisting of at least one micropore that communicates with the opening in the wall and the exterior of the device;
• B. dissolving said agent in the compartment in gastrointestinal fluid being imbibed through the wall into the compartment at a rate determined by the permeability of the wall and the osmotic pressure gradient across the wall to continuously dissolve the agent;
• and
• C. releasing the agent from the device at a therapeutically effective controlled and continuous rate through the passageway to the gastrointestinal tract over a prolonged period of time.