Poly(ester-anhydrides) and intermediates therefor
CA 2233653 A1 · Owner: Deng, Z. David · Inventors: Storey, Robson F.; Glancy, Todd P.; Peterson, Dale R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Biodegradable poly(ester-anhydrides) designed to display two-stage degradation profiles are described. The presence of the anhydride linkages allows a relatively rapid decrease in molecular weight the extend of which is governed , by the concentration of the anhydride linkages along the chain followed by , possible dissolution and a slower degradation of the remaining oligomers the , rate of which is governed by the composition of the polyester prepolymers. Methods for the preparation of the poly(ester-anhydrides) and their polyester precursors are also described.
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 February 21, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 21, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 21, 2019.
- 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.