《SINGULAIR (MONTELUKAST SODIUM) TABLETS》.pdf

9628411 SINGULAIR® (MONTELUKAST SODIUM) TABLETS, CHEWABLE TABLETS, AND ORAL GRANULES DESCRIPTION * Montelukast sodium, the active ingredient in SINGULAIR , is a selective and orally active leukotriene receptor antagonist that inhibits the cysteinyl leukotriene CysLT1 receptor. Montelukast sodium is described chemically as [R-(E)]-1-[[[1-[3-[2-(7-chloro-2­ quinolinyl)ethenyl]phenyl]-3-[2-(1-hydroxy-1-methylethyl)phenyl]propyl]thio]methyl]cyclopropaneacetic acid, monosodium salt. The empirical formula is C H ClNNaO S, and its molecular weight is 608.18. The structural formula 35 35 3 is: - + S COO Na Cl N HO H3C H C 3 Montelukast sodium is a hygroscopic, optically active, white to off-white powder. Montelukast sodium is freely soluble in ethanol, methanol, and water and practically insoluble in acetonitrile. Each 10-mg film-coated SINGULAIR tablet contains 10.4 mg montelukast sodium, which is equivalent to 10 mg of montelukast, and the following inactive ingredients: microcrystalline cellulose, lactose monohydrate, croscarmellose sodium,