Trihydrates of sodium l- and d-2-pyrrolidone-5-carboxylate
CA 2000184 C · Owner: Degussa Aktiengesellschaft · Inventors: Krimmer, Hans-Peter; Drauz, Karlheinz
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A description is given of the new crystalline trihydrates of sodium-L- and -D-2-pyrrolidone-5-carboxylate. These trihydrates can be obtained by preparing an aqueous solution of sodium-L- or -D-2-pyrrolidone-5-carboxylate and matching the temperature and concentration to each other in such a way that the solubility of the respective trihydrate is exceeded.
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 October 5, 1989 and granted July 8, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 5, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 5, 2011.
- 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.