SPL Set ID: fb1b2e4e-a840-447b-b943-ad0b6acc32b5

Montelukast sodium USP, the active ingredient in montelukast sodium tablets, is a selective and orally active leukotriene receptor antagonist that inhibits the cysteinyl leukotriene CysLT 1 receptor. Montelukast sodium USP 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 molecular formula is C 35 H 35 CINNaO 3 S, and its molecular weight is 608.18. The structural formula is: Montelukast sodium USP is white or almost white amorphous powder, hygroscopic in nature. Montelukast Sodium USP is freely soluble in water, methylene chloride and ethanol (96%). Each 10 mg film-coated montelukast sodium tablet USP, contains 10.4 mg montelukast sodium USP, which is equivalent to 10 mg of montelukast, and the following inactive ingredients: croscarmellose sodium, hydroxypropyl cellulose, lactose monohydrate, magnesium stearate and microcrystalline cellulose. The film coating consists of: hypromellose, iron oxide yellow, iron oxide red, iron oxide black, polyethylene glycol 400 and titanium dioxide. Each 4 mg and 5 mg montelukast sodium chewable tablet contains 4.2 and 5.2 mg montelukast sodium USP, respectively, which are equivalent to 4 and 5 mg of montelukast, respectively. Both chewable tablets contain the following inactive ingredients: aspartame, cherry flavor, croscarmellose sodium, hydroxypropyl cellulose, mannitol, magnesium stearate, microcrystalline cellulose and red ferric oxide. Structural Formula