Sustained release dispensing device and method
CA 1046408 A · Owner: Alza Corporation · Inventors: Heller, Jorge; Baker, Richard W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A device for the controlled continuous administration of an active agent to a constant pH aqueous environment is disclosed. The device comprises a body of erodible agent, release rate controlling material containing the agent dispursed therethrough. The rate controlling material is a hydrophobic poly(carboxylic acid) having one ionizable carboxylic hydrogen for each 8 to 23 carbon atoms which, material erodes at a controlled rate over a prolonged period of time in response to an essentially constant pH environment by a process of carboxylic hydrogen ionization thereby, prolonged period of time.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted January 16, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 16, 1996.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.