High molecular weight polymer-based prodrugs
CA 2263409 C · Owner: Zhao, Hong · Inventors: Greenwald, Richard B.; Pendri, Annapurna; Zhao, Hong
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is directed to compositions of formula (I) wherein D is a residue of biologically active moiety; X is an electron withdrawing group; Y and Y' are independently O or S; (n) is zero (0) or a positive integer, preferably from 1 to about 12; R1 and R2 are independently selected from the group consisting of H C1-6 alkyls, aryls, substituted , aryls aralkyls, heteroalkyls, substituted heteroalkyls and substituted C1-6 alkyls; R3 , is a substantially non-antigenic polymer C1-12 straight or branched alkyl , or substituted alkyl C5-8 cycloalkyl or substituted cycloalkyl carboxyalkyl, carboalkoxy alkyl, dialkylaminoalkyl phenylalkyl, phenylaryl or (a); and R4 and R5 are …
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 August 20, 1997 and granted February 22, 2011. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 20, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 20, 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.