Process for derivatizing polyglucosamines
CA 2173642 C · Owner: Gruber, James Vincent · Inventors: Gruber, James Vincent
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Processes for the preparation of polyglucosamine derivatives e.g. hydroxypropyl chitosan and carboxymethyl chitosan are disclosed. The polyglucosamine derivatives can be prepared in a covalently bonded form using a dilute caustic medium or ionically bonded form. Strong bases and undesirable water-immiscible organic solvents can be avoided. The covalently bonded derivatives dissolve into the dilute caustic medium upon formation. Compositions containing the derivatives and uses for the derivatives are 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 April 9, 1996 and granted November 2, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 9, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 9, 2018.
- 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.