Osmotic system with distribution zone for dispensing beneficial agent
Patent 4200098 Issued on April 29, 1980. Estimated Expiration Date: 
October 23, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 23, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3854770 3916899 Hydrophilic or hydrogel carrier systems such as coatings, body implants and other articles Patent #: 3975350 InventorsApplicationNo. 05/953906 filed on 10/23/1978US Classes:424/424, Membrane or diffusion barrier424/431, Tampon424/433, Depot, pellet, matrix, or suppository424/436, Anal, rectal (e.g., suppositories, etc.)424/473, With porous, perforated, apertured, or sieved layer (e.g., dialyzing layer, microporous layer, etc.)428/420Including interfacial reaction product of adjacent layersExaminersPrimary: Michell, Robert W.Assistant: Rosenbaum, C. Fred Attorney, Agent or FirmInternational ClassA61K 9/00 (20060101)AbstractAn osmotic system is disclosed for dispensing a beneficial agent. The system comprises (1) a first wall of a semipermeable material that surrounds a compartment containing a drug formulation, and has a passageway through the wall for releasing agent from the compartment, (2) a second wall positioned distant from the first wall, said second wall a microporous or hydrogel material that extends around the first wall, and (3) a distribution zone interposed between the first and second wall and initially housing a compound soluble in an external fluid that enters the system.In operation, agent is dispensed from the system by fluid passing through the second wall into the zone from which fluid is further being imbibed through the first wall into the compartment forming a solution that is released through the passageway into the zone, and then through the second wall to the exterior of the system. | |
