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Expired Canadian patentCanada

Controlled release formulation of divalproex sodium

CA 2330480 C · Owner: Engh, Kevin R. · Inventors: Engh, Kevin R.; Poska, Richard P.; Bollinger, J. Daniel

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A controlled release tablet formulation which permits once daily dosing in the treatment of epilepsy comprises from about 50 weight percent to about 55 weight percent of an active ingredient selected from the group consisting of valproic acid, a pharmaceutically acceptable salt or ester of valproic acid divalproex sodium, and valpromide; from about 20 weight percent to about 40 weight percent hydroxypropyl methylcellulose; from about 5 weight percent to about 15 weight percent lactose, from about 4 weight percent to about 6 weight percent microcrystalline cellulose, and from about 1 weight percent to about 5 weight percent silicon dioxide having an average particle size ranging …

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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 December 9, 1999 and granted May 21, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 9, 2019.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 9, 2021.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 9, 1999
GrantedMay 21, 2002
Term endedDecember 9, 2019
Patent numberCA 2330480 C
Classification (IPC)A61K9/22 +2 more

Timeline

Timeline From CIPO dates

2000200220042006200820102012201420162018Application filedDec 9, 1999Patent grantedMay 21, 2002Term endedDec 9, 2019

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.