Materials and methods relating to polyions and substance delivery
CA 2487304 A1 · Owner: Harper, Garry Robert · Inventors: Harper, Garry Robert; Cooper, Paula; Baker, Matthew John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Materials and method are disclose for delivering a desired substance to a target site, using a layered carrier in which the carrier and the substance together form at least three layers which associate by ionic interaction at the first pH, where at least one layer comprises a charge switch material which comprises an ionisable group and which has a positive charge at a first pH and a charge which is less positive neutral or negative at a second pH, at least one layer comprises a polyionic polymer which is negatively charged at the first pH and at least one layer comprises the desired substance. Preferred carriers are based on the charge switch material poly Bis-Tris and the …
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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 June 2, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 2, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 2, 2025.
- 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.