LC-MS/MS Analytical Method for Determination of Montelukast in Human Plasma and its Application to a Bioequivalence Study

Background: This study aimed to develop a sensitive, rapid method based on HPLC-MS/MS for the quantification of Montelukast in human plasma utilizing Montelukast-D6 as an internal standard. Montelukast is a leukotriene inhibitor and is used to prevent asthma attacks in adults and children. Method: Separation was achieved using Thermo Hypersil GOLD™ Cyano HPLC columns (50 × 4.6 mm; 5 μm) with a mobile phase consisting of 0.5 mM ammonium chloride: ACN (20:80%; v/v). Results: The method was found to be linear over a concentration range of 10.0 - 600.0 ng/mL with a correlation coefficient (r2) ≥ 0. 0.9989. The stabilities of Montelukast and internal standard were assessed in several conditions with recovery results > 85%. The precision results were less than 4.0%, while the accuracy results were within 93.0 107.0%. The method proved to be selective with no matrix effect. Conclusion: This method was found to be highly reproducible and was utilized successfully for the analysis of plasma samples following the oral administration of Montelukast (10 mg) in 28 healthy male human volunteers.