Montelukast

Montelukast (CAS 158966-92-8, EC 605-168-4, molecular formula C35H36ClNO3S) is a selective leukotriene receptor antagonist, also known by the trade name Singulair and synonyms including Velukast, Montelukas, and Montélukast. It carries no assigned E-code and is classified as a pharmaceutical intermediate.

Montelukast is used primarily in the synthesis and manufacture of anti-asthma and allergic rhinitis medications, where it functions by selectively blocking cysteinyl leukotriene CysLT1 receptors, thereby inhibiting bronchoconstriction and inflammatory signalling pathways. It also serves as a reference standard and active pharmaceutical ingredient (API) in generic drug development programmes.

Montelukast is supplied as a solid and is available in pharmaceutical-grade form meeting Ph.Eur. and ICH quality standards, with REACH compliance applicable for European supply chains. Procurement quantities and packaging formats should be confirmed directly with the supplier to meet specific batch and documentation requirements.