CPC A61K 31/55 (2013.01) [A61K 47/02 (2013.01); A61K 47/12 (2013.01); A61K 47/38 (2013.01); C07D 471/18 (2013.01)] | 30 Claims |
1. A method of making a varenicline tartrate tablet comprising less than 50 ppm of nitrosamine impurities, the method comprising:
(a) mixing varenicline free base with tartaric acid to form varenicline tartrate; and
(b) means for reducing the nitrosamine impurities to less than 50 ppm per tablet as measured by LC-ESI-HRMS Method;
wherein the means comprises an acid-base treatment.
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