Claims for Patent: 4,519,801

Summary for Patent: 4,519,801

Title:	Osmotic device with wall comprising cellulose ether and permeability enhancer
Abstract:	An osmotic delivery system is disclosed for dispensing a useful agent. The system comprises a semipermeable wall surrounding a compartment housing the agent. The wall comprises a cellulose ether, an organic solvent soluble polymer, and optionally an aqueous soluble polymer. A passageway in the wall connects the interior of the system with the exterior for dispensing an agent from the system.
Inventor(s):	Edgren; David (El Granada, CA)
Assignee:	ALZA Corporation (Palo Alto, CA)
Application Number:	06/397,517
Patent Claims:	1. An osmotic delivery system for the controlled dispensing of a useful agent to an environment of use, wherein said system comprises: (a) a shaped semipermeable wall permeable to the passage of fluid and substantially impermeable to the passage of an useful agent, said semipermeable wall consisting essentially of an organic solvent soluble cellulose ether and a permeability enhancer selected from the group consisting of an organic solvent soluble carboxypolymethylene, polyvinyl acetal, polyvinyl butyral, polyalkyds, polymethacrylonitrile, vinyl alcohol-vinyl acetate copolymer, and vinyl alcohol-vinyl butyral copolymer, the semipermeable wall surrounding and forming: (b) a compartment containing a useful agent formulation that is soluble in an external fluid imbibed through the semipermeable wall into the compartment and exhibits an osmotic pressure gradient across the semipermeable wall against the external fluid; and, (c) an osmotic passageway in the wall communicating with the compartment and the exterior of the system for dispensing the agent formulation through the osmotic passageway from the device to the environment of use. 2. The osmotic delivery system for the controlled dispensing of a useful agent according to claim 1, wherein the agent is a drug. 3. The osmotic delivery system for the controlled dispensing of a useful agent according to claim 1, wherein the agent formulation comprises an osmotically effective solute. 4. An osmotic delivery system for the controlled dispensing of a useful agent to an environment of use, wherein said system comprises: (a) a shaped semipermeable wall permeable to the passage of an external fluid and substantially impermeable to the passage of a useful agent formulation, comprising an organic solvent soluble cellulose ether and a permeability enhancer selected from the group consisting of an organic solvent soluble carboxypolymethylene, polyvinyl acetal, polyethylene oxide, polyethylene glycol, polyvinyl butyral, polyalkyds, polymethacrylonitrile, vinyl alcohol-vinyl acetate copolymer, vinyl alcohol-vinyl butyral copolymer, and a hydrophilic polyester formed from hydroxy and carboxy polymers, said semipermeable wall additionally contains a member selected from the group of an aqueous soluble polyvinyl alcohol, polyvinyl pyrrolidone, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, guar gum, dextran and, the wall surrounding and forming: (b) a compartment containing a useful agent formulation that is soluble in an external fluid imbibed through the wall into the compartment and exhibits an osmotic pressure gradient across the wall against the external fluid; and, (c) an osmotic passageway in the wall communicating with the compartment and the exterior of the system for dispensing the agent formulation through the passageway from the device to the environment of use. 5. An osmotic delivery system for the controlled dispensing of a useful agent to an environment of use, wherein said system comprises: (a) a shaped semipermeable wall permeable to the passage of fluid and substantially impermeable to the passage of an useful agent, consisting essentially of an organic solvent soluble cellulose ether and a blend of water soluble polymers, which water soluble polymers on the application of energy used to coat the semipermeable wall of the delivery system, forms a hydrophilic and substantially fluid insoluble polymer in the semipermeable wall on the device, the semipermeable wall containing the insoluble polymer surrounding and forming: (b) a compartment containing a useful agent formulation that is soluble in an external fluid imbibed through the semipermeable wall into the compartment and exhibits an osmotic pressure gradient across the semipermeable wall against the external fluid; and, (c) an osmotic passageway in the wall communicating with the compartment and the exterior of the system for dispensing the agent formulation through the passageway from the system to the environment of use. 6. An osmotic delivery system for the controlled dispensing of a beneficial agent to an environment of use, wherein the osmotic system comprises; (a) a shaped wall formed of a semipermeable composition permeable to the passage of an external fluid and substantially impermeable to the passage of an useful agent, consisting essentially of an organic solvent soluble cellulose ether, a polyhydroxy polymer and a polycarboxy polymer, which polyhydroxy polymer and polycarboxy polymer react while coating the wall onto the device to form a hydrophilic fluid permeability enhancing polymer blended within the cellulose ether, said wall surrounding and defining: (b) a compartment containing a useful agent formulation that is soluble in an external fluid imbibed through the wall into the compartment and exhibits an osmotic pressure gradient across the wall against the external fluid; and, (c) an osmotic passageway in the wall communicating with the compartment and the exterior of the system for dispensing the agent formulation through the wall from the system to the environment of use over a prolonged period of time. 7. An osmotic delivery system for the controlled dispensing of the useful agent to an environment of use, wherein said system comprises: (a) a shaped semipermeable wall permeable to the passage of fluid and substantially impermeable to the passage of a useful agent formulation, consisting essentially of an organic solvent soluble cellulose ether and a blend of water soluble polymers which water soluble polymers on the application of energy form a hydrophilic and substantially fluid insoluble polymer in the wall, said wall additionally containing a member selected from the group consisting essentially of hydroxyethyl cellulose, ethyl methylcellulose, polyacrylic acid, polyethyl methacrylate, polymethyl methacrylate, polyalkylated polyvinylpyrrolidone, poly(vinylpyrrolidone-vinyl acetate), poly(methyl vinylether maleic acid), poly(methyl vinylether maleic anhydride), polyethylene oxide, gum Arabic, glycerin, sucrose, fructose, and glucose, the semipermeable wall surrounding and forming: (b) a compartment containing a useful agent formulation that is soluble in an external fluid imbibed through the wall into the compartment and exhibits an osmotic pressure gradient across the wall against the external fluid; and, (c) an osmotic passageway in the wall communicating with the compartment and the exterior of the system for dispensing the agent formulation from the system to the environment of use. 8. An osmotic system for the controlled delivery of a beneficial agent to an environment of use, wherein the system consists essentially of: (a) a shaped semipermeable wall, consisting essentially of a cellulose ether and a polyethylene glycol, said semipermeable wall permeable to the passage of an external fluid and substantially impermeable to the passage of a useful agent formulation; which wall surrounds and forms: (b) a compartment for containing a beneficial agent formulation; and, (c) an osmotic passageway in the wall that connects the compartment and the exterior of the system for dispensing the agent formulation through the osmotic passageway from the osmotic system to the environment of use over time. 9. An osmotic system for the controlled delivery of a beneficial agent to an environment of use, wherein the system consists essentially of: (a) a shaped semipermeable wall consisting essentially of a cellulose ether and a polyethylene oxide, said semipermeable wall permeable to the passage of an external fluid and substantially impermeable to the passage of agent formulation, which semipermeable wall surrounds and forms: (b) a compartment for containing a beneficial agent formulation; and, (c) an osmotic passageway in the semipermeable wall that connects the compartment and the exterior of the osmotic system for dispensing the agent formulation through the osmotic passageway from the system to the environment of use over time.