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US 9,751,828 B2Granted
Antimuscarinic compound having a low content of impurities
AssigneeDipharma Francis S.R.L.
InventorsPietro Allegrini, Emanuele Attolino, Renzo Graziosi
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Abstract
Substantially stable to degradation Fesoterodine fumarate, a process for its preparation and a process for the synthesis of specific degradation impurities of Fesoterodine fumarate are disclosed.
Claims10
A process for the preparation of a substantially stable to degradation Fesoterodine fumarate, comprising:
- salifying Fesoterodine base with fumaric acid in the presence of a solvent wherein the molar ratio between Fesoterodine base and fumaric acid is comprised between about 1:0.10 and about 1:0.88;
- precipitating Fesoterodine fumarate from the resulting solution;
- and recovering the solid;
- wherein said Fesoterodine fumarate does not develop degradation impurities of formula (IV), in an amount greater than 0.1% after 90 days at 25 ° C. with a relative humidity of 60%:
1 more element
A substantially stable to degradation Fesoterodine fumarate, wherein said Fesoterodine fumarate does not develop degradation impurities of formula (IV), in an amount greater than 0.1% after 90 days at 25 ° C. with a relative humidity of 60%:
- wherein said Fesoterodine fumarate is obtained using a substoichiometic amount of fumaric acid.
Dependencies are inferred from the claim text.