FDC of montelukast with levocetirizine: focus on bilayer technology.

Allergic rhinitis is the most common allergic disease worldwide and affects about 18% to 40% of the general population. Anti-allergic medicines (eg, some antihistamines) can cause adverse events such as somnolence and can have an additional negative impact on quality of life. Combining montelukast with levocetirizine gives additional benefits in comparison with either drug alone and could be considered for patients whose quality of life is impaired by persistent allergic rhinitis. Montelukast sodium is alkaline, stable and levocetirizine dihydrochloride is acid stable, when we prepare a matrix tablet, both the drugs would be in contact and make it unstable during the shelf life of the formulation. Hence it is recommended to prepare bilayer tablet, as it improves and increases the stability of both the drugs in combination. Bilayer tablet of montelukast with levocetirizine is more stable with respect to stability studies, in comparison to matrix tablet.