Delivery system
CA 1113395 A · Owner: Pfizer Limited · Inventors: Dresback, David S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Delivery systems and devices for the controlled release of chemicals, including drugs, comprising a wall, formed in part at least, of a porous material including a porous fabric material, pores of which contain a hydrogel, said porous wall in contact with at least a portion of a reservoir comprised of a chemical and, if desired, a water-soluble liquid excipient and/or a detergent; process for preparation thereof, and use for the controlled release of chemicals including drugs, to an aqueous liquid-containing environment. Emphasis is given to said systems and devices in which the hydrogel is gelled cellulose triacetate, and to their use for controlled release of drugs to animal, especially …
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 December 1, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 1, 1998.
- 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.