Montelukast Sodium

CAS 151567-02-1

About the API

Systematic name 2-[1-[[(1R)-1-[3-[(E)-2-(7-chloroquinolin-2-yl)ethenyl]phenyl]-3-[2-(2- hydroxypropan-2-yl)phenyl]propyl]sulfanylmethyl]cyclopropyl]acetic acid Trade
Technology Synthetic Organic Chemistry
Molecular Formula C35H35ClNNaO3S
Molecular Weight 608.17 g/mol
Physical properties off-white to pale yellow colored powder
Therapeutic category Respiratory
Available formulations Oral Liquid Oral Solid Oral Solid Long-Acting
Regulations CEP Flag CEP EU DMF Flag EU DMF Japan DMF Flag Japan DMF Korea DMF Flag Korea DMF US DMF Flag US DMF

General Information

Montelukast sodium is an orally active compound that belongs to a class of molecules termed leukotriene receptor antagonists (LTRAs) and is approved for the treatment of symptoms related to asthma and allergic rhinitis (hay fever). It is also prescribed to prevent exercise-induced bronchospasm. Montelukast sodium inhibits the binding of leukotrienes (molecules secreted by white blood cells) to a receptor that triggers an inflammatory response. Due to its mechanism of action, this drug is not prescribed for the treatment of acute asthma attacks.


Montelukast sodium became FDA approved for the treatment of asthma, allergic rhinitis, and exercise-induced bronchoconstriction under the trade name Singulair in 1998. It is currently manufactured through large-scale synthetic organic chemistry methods starting from simple, commercially available precursors.