Specific impurities of montelukast
AssigneeZentiva k.s.
InventorsAles Halama, Olga Bouskova, Petr Gibala, Josef Jirman
Life of this patent
Estimating the term…
Abstract
The subject-matter of the invention consists in a method of removing specific impurities of montelukast of formula (I), which occur due to chemical instability of the target substance and also contaminate the substance in the preparation process. Further, methods of isolation of specific impurities of montelukast defined by formulae (V-A), (IV-A), (XIIIa-A), (XIIIb-A) and analytic methods used for the control of the production of montelukast in the pharmaceutical quality.
Claims10
1-41. (canceled)
An isolated specific impurity of montelukast, selected from the group including 2-[(R)-1-[[[1-[3-[2-(7-chloro-2-quinolinyl)-(S)-1-({[1-(carboxymethyl)cyclopropyl]methyl}thio)ethyl]-phenyl]-3-[2-(1-hydroxy-1-methylethyl)phenyl]propyl]thio]methyl]cyclopropane]-acetic acid of formula XIIIa:
- and 2-[(R)-1-[[[1-[3-[2-(7-chloro-2-quinolinyl)-(R)-1-({[1-(carboxymethyl)cyclopropyl]methyl}thio)ethyl]-phenyl]-3-[2-(1-hydroxy-1-methylethyl)phenyl]propyl]thio]methyl]cyclopropane]-acetic acid of formula XIIIb:
- and their alkali metal salts, characterized by chemical purity of more than 50% for use in setting the analytic methods designed for quality control of montelukast.
Dependencies are inferred from the claim text.