Very low temperature casting of controlled release microspheres
CA 2030550 C · Owner: Alkermes Controlled Therapeutics Inc. · Inventors: Healy, Michael S.; Brown, Larry R.; Gombotz, Wayne R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Invention, A process for preparing microspheres using very cold temperatures to freeze polymer-biologically active agent mixtures into polymeric microspheres with very high retention of biological activity and material. Polymer is dissolved in a solvent together with an active agent that can be either dissolved in the solvent or dispersed in the solvent in the form of microparticles. The polymer/active agent mixture is atomized into a vessel containing a liquid non-solvent alone or frozen and overlayed with a liquified gas at a temperature, below the freezing point of the polymer/active agent solution. The cold liquified gas or liquid immediately freezes the polymer …
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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 May 1, 1990 and granted September 21, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 1, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 1, 2012.
- 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.