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Osmotic device with wall comprising cellulose ether and permeability enhancer

  • US 4,519,801 A
  • Filed: 07/12/1982
  • Issued: 05/28/1985
  • Est. Priority Date: 07/12/1982
  • Status: Expired due to Term
First Claim
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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.

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