Retinoic acid-containing compositions
CA 2134677 C · Owner: Bertek Pharmaceuticals Inc. · Inventors: Quigley, John W. Jr.; Goodman, Harris
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Novel retinoic acid-containing topical compositions in the form of creams lotions, gels, and the like, are disclosed. These compositions contain a urethane compound having a molecular weight of up to about 60,000 prepared by reacting approximately, two moles of a hydroxy-terminated linear alkylene or polyalkylene glycol with approximately one mole of a monomeric organic diisocyanate. The presence of the urethane compound leads to decreased percutaneous transmission of the retinoic acid resulting, in reduced skin irritation but undiminishes therapeutic effectiveness of the retinoic acid when compared to retinoic acid-containing topical formulations otherwise identical except for the absence …
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 April 20, 1993 and granted December 15, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 20, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 20, 2015.
- 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.