Process for preparing pure crystalline lorazepam
CA 2401928 A1 · Owner: Teva Pharmaceutical Industries Ltd. · Inventors: Lifshitz, Igor
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a process for preparing crystalline lorazepam substantially free of bound solvent from a lorazepam alcohol solvate or hydrate by suspending the lorazepam solvate in an organic medium selected form ethyl acetate, cyclohexane, dichloromethane toluene and mixtures thereof. , This process is useful in producing the anti-anxiety and sedative agent lorazepam in increased yields. A process for converting lorazepam lower alcohol solvates to lorazepam hydrate is also disclosed.
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 March 5, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 5, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 5, 2023.
- 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.