Sustained-release oral drug dosage form
CA 2014451 C · Owner: Shell, John W. · Inventors: Shell, John W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Sustained-release oral drug-dosage forms that release drug in solution at a rate controlled by the solubility of the drug are described. The dosage form comprises a tablet or capsule which comprises a plurality of particles of a dispersion of a limited solubility drug in a hydrophilic, water-swellable, crosslinked polymer that maintains its physical integrity over the dosing lifetime but thereafter rapidly dissolves. Once ingested the particles swell to promote gastric retention and permit the gastric fluid to penetrate the particles dis-, solve drug and leach it from the particles assuring that, drug reaches the stomach in the solution state which is less injurious to the stomach than …
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
- Filed April 11, 1990 and granted August 6, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 11, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 11, 2012.
- 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.