System for delivering agent at zero order rate with emerging agent below saturation
Patent 4298003 Issued on November 3, 1981. Estimated Expiration Date: 
May 12, 2000. 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.
May 12, 2000. 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 3732865 Osmotic dispenser Osmotic system having laminated wall comprising semipermeable lamina and microporous lamina System with microporous reservoir having surface for diffusional delivery of agent Galenical form of administration of betahistine and its derivatives Patent #: 4229428 InventorsAssigneeApplicationNo. 06/149020 filed on 05/12/1980US Classes:424/424, Membrane or diffusion barrier424/431, Tampon424/437, Otic424/473With porous, perforated, apertured, or sieved layer (e.g., dialyzing layer, microporous layer, etc.)ExaminersPrimary: Rosenbaum, C. FredAttorney, Agent or FirmInternational ClassA61K 9/00 (20060101)AbstractAn osmotic system is disclosed for delivering an agent. The system comprises a semipermeable wall surrounding a compartment. The compartment contains a layer of a compound that is insoluble in an exterior fluid, and juxtaposed with a layer of an agent that is soluble in the fluid. A passageway through the wall connects the exterior of the system with the interface between the wall and the insoluble compound. In operation, agent is delivered from the system, by the agent imbibing fluid into the compartment to form a saturated solution of agent, that is moved along the interface between the wall and the insoluble compound towards the passageway. The saturated solution is moved continuously by the corresponding imbibition of fluid, and as the solution moves along the interface it imbibs fluid, is diluted and delivered below a saturated concentration to the exterior of the system. The invention also concerns a two layered structure comprising a layer of an aqueous insoluble compound and a layer of an aqueous soluble compound. | |
