Montelukast EP Impurity E; Montelukast USP RC D; Michael Adduct (R,S)-Isomer

Montelukast EP Impurity E; Montelukast USP RC D; Michael Adduct (R,S)-Isomer

1-[[[(1R)-1-[3-[(1S)-1-[[[1-(Carboxymethyl)cyclopropyl]methyl]thio]-2-(7-chloro-2-quinolinyl)ethyl]phenyl]-3-[2-(1-hydroxy-1-methylethyl) phenyl] propyl] thio]methyl]-cyclopropaneacetic acid

Impurity reference standard used for related substances testing of Montelukast Acid drug substance and drug product per pharmacopoeial limits.