The US Food and Drug Administration (USFDA) has approved the marketing of Ranbaxy Laboratories' migraine drug, Imitrex (Sumatriptan), a low cost version of migraine drug GlaxoSmithKine, in the US market.

A spokesman of Rabnbaxy said, "We have received the US Food and Drug Administration's (USFDA) approval for 100 mg Sumatriptan."

The regulator provides 180-day marketing exclusivity for its marketing in 100 mg dosage which was earlier rejected by it on December 2008.

It should be recalled that Ranbaxy entered in a settlement with GlaxoSmithKline (GSK) in January 2008, helping it to launch the generic drug in America.

However, it could not launch the anti-migraine drug following reservation expressed by USFDA regarding quality of products being produced at its two manufacturing facilities in India. The regulator had also banned the import of 30 drugs produced at its two Indian facilities leading to its stormy relations with the regulator.     

India's largest drug maker, Ranbaxy Laboratories is expected to earn $25-30 million during the period it is permitted to sell the product in US. The company would manufacture the medicine at its US based facility and it has again applied for marketing permission in the country.