Qualitest Pharmaceuticals has introduced generic version of Singulair (montelukast sodium) tablets and chewable tablets and will immediately begin the product shipment.

The launch of the Montelukast Sodium Tablets indicated for treating symptoms of asthma and allergic rhinitis follows the expiration of the last patent that provides Merck US market exclusivity.

According to IMS Health, the total combined sales for Montelukast Sodium Tablets and Chewables were approximately $4.9bn in the US, for the 12 months ending 30 June 2012.

Qualitest is an operating company of Endo Health Solutions, a US-based diversified healthcare company that finds solutions for the unmet needs of patients along care pathways for pain management, pelvic health, urology, endocrinology and oncology.