Derivatized dtpa complexes
CA 2020142 C · Owner: Schmitt-Willich, Heribert · Inventors: Platzek, Johannes; Schuhmann-Giampieri, Gabriele; Weinmann, Hanns-Joachim
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Compounds of the formula, (see above formula) wherein:, one of Z1 and Z2 is H, and the other is - (CH2)m-(C6H4)q-(O)k-(CH2)n-(C6H4)l-(O)r-R wherein, m and n, independently, are each 0-20 k, l, q and r are each, independently, 0 or 1 R is H, C1-C6-alkyl, OR1-substituted C1-C6-alkyl or CH2COOR1, where R1 is H, C1-C6-alkyl or benzyl; and, X is, in each case, a hydrogen atom or a metal ion equivalent of an element of atomic number 21-29 42, 44 or, 57-83;, with the provisos that: at least two of the substituents X represent a metal ion equivalent;, when n and 1 each are 0 then k and r are not, simultaneously 1; at least one of q and l is 1;, -(O)r-R is not OH; and Z1, and Z2 are not …
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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 29, 1990 and granted April 17, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 29, 2012.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.