Patent Yard Sign in
Expired Canadian patentCanada

Cellulose matrix encapsulation and method

CA 2519652 C · Owner: Pg Research Foundation · Inventors: Spear, Scott K.; Holbrey, John David; Rogers, Robin Don

CIPO record

Overview

Drawings and full text

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

Open the CIPO record

Abstract From the Canadian patent

A regenerated cellulose-encapsulated active substance and a method for encapsulating an active substance in a regenerated cellulose matrix are disclosed. The distribution of the active substance is preferably substantially homogeneous within the matrix of regenerated cellulose. The regenerated cellulose (i) has about the same molecular weight as the original cellulose from which it is prepared (ii) is substantially free of added substituent groups relative to the starting cellulose and is also substantially free of entrapped ionic liquid degradation products.

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 March 19, 2004 and granted July 24, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 19, 2024.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 19, 2026.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 19, 2004
GrantedJuly 24, 2012
Term endedMarch 19, 2024
Patent numberCA 2519652 C
Classification (IPC)C08J3/21 +2 more

Timeline

Timeline From CIPO dates

2005200720092011201320152017201920212023Application filedMarch 19, 2004Patent grantedJuly 24, 2012Term endedMarch 19, 2024

Sources & verification

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