Process for reducing the crystal size of ondansetron hydrochloride dihydrate
CA 2019944 C · Owner: Glaxo Group Limited · Inventors: Collin, David Trevor
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a process for reducing the crystal size of ondansetron hydrochloride dihydrate. Ondansetron the approved name for 1,2,3,9-tetrahydro-9methyl-3-(2-methyl-1H-imidazol-1-yl)methyl-4H-carbazol-4-one is produced by crystallisation from solvent to a size which is suitable for effective distribution in a tablet blend in, particular 100% of the crystals having a size of less than 250µm. The ondansetron hydrochloride dihydrate is desolvated by drying at elevated temperature and reduced or atmospheric pressure and is then rehydrated.
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 June 27, 1990 and granted May 9, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 27, 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.