Method of purifying nucleoside derivatives
CA 2101281 C · Owner: Shiragami, Hiroshi · Inventors: Izawa, Kunisuke; Honda, Yutaka; Yukawa, Toshihide
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A crude 2',3'-dideoxynucleoside compound is purified by extracting with an organic solvent or crystallizing, the 2',3'-dideoxynucleoside compound from a basic aqueous solution having a pH of not less than 12 containing the same. In another embodiment of purification a basic aqueous solution having a pH of not less than 11 of a crude 2',3'-dideoxynucleoside derivative is brought into contact with a nonpolar porous resin whereby the derivative is adsorbed on the resin and then the thus adsorbed derivative is desorbed with an aqueous alcoholic solution. 2',3'-Dideoxynucleoside compounds which have utility as anti-AIDS drugs or anti-virus drugs can be isolated and purified in high purity and in …
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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 July 26, 1993 and granted November 4, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 26, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 26, 2015.
- 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.