Xanthine compounds
CA 2024381 C · Owner: Nonaka, Hiromi · Inventors: Ishii, Akio; Shimada, Junichi; Ohno, Tetsuji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Novel xanthine compounds represented by the following formula:, wherein each of R1 R and R3 independently represents, hydrogen or lower alkyl; each of X1 and X independently represents oxygen or sulfur; and Q represents:, , , , , or , where represents a single bond or a double bond; Y represents a single bond or alkylene n represents 0 or 1, each of W1 and W independently represents hydrogen lower, alkyl or amino, Z represents -CH2- -O-, -S- or -NH-;, provided that when Q is then R1, R and R3 are not, simultaneously methyl; and pharmaceutically acceptable salts thereof have a diuretic effect, a renal-protecting effect and a bronchodilatory effect. - 52 -, The compounds are useful as a …
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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 August 31, 1990 and granted January 7, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 31, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 31, 2012.
- 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.