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Expired Canadian patentCanada

Ophthalmological collagen coverings

CA 1322716 C · Owner: Bagrov, Sergey Nikolayevich · Inventors: Maklakova, Irina Aleksandrovna; Bagrov, Sergey Nikolayevich; Maslenkov, Sergey Valentinovich

CIPO record

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Abstract From the Canadian patent

Ophthalmologic collagen coverings derived from animal eyes and a process for preparing such coverings comprising treatment of a fibrous tunic of an animal eye with an alkali metal hydroxide in a saturated solution of a salt of an alkali metal, followed by neutralization dissolution in an aqueous solution of an organic acid purification of, the resulting solution of collagen by dialysis against a buffer solution while bringing the solution of collagen to a pH of 4.5 to 7.5 and drying the thus-obtained solution of collagen simultaneously with shaping spherical coverings therefrom.

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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

  • Granted October 5, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 5, 2010.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 16, 1987
GrantedOctober 5, 1993
Term endedOctober 5, 2010
Patent numberCA 1322716 C
Classification (IPC)A61K38/39 +2 more

Timeline

Timeline From CIPO dates

19881991199419972000200320062009Application filedSep 16, 1987Patent grantedOct 5, 1993Term endedOct 5, 2010

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