Anticalculus dentifrices
CA 2116225 C · Owner: Walley, Darlene R. · Inventors: Miskewitz, Regina M.; Winston, Anthony E.; Walley, Darlene R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Dentifrices, including toothpaste or dental creams gels and tooth powders, incorporating alkali metal pyrophosphate salts and sodium bicarbonate in amounts effective to inhibit calculus formation on teeth. The sodium bicarbonate improves the calculus inhibiting properties of the pyrophosphate salts permits the use of smaller quantities of pyrophosphate than required in the absence of the bicarbonate adjuvant allows the formulation of pyrophosphate containing dentifrices without the need to use unpleasant tasting potassium pyrophosphates to prevent grittiness and salts-out the pyrophosphate as undissolved tetrasodium pyrophosphate decahydrate in the form of relatively small particles which …
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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 October 22, 1991 and granted June 15, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 22, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 22, 2013.
- 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.