Mumbai: Three weeks after getting approval to launch a cheaper generic version of Novartis AG’s blood pressure drug Diovan in the US, Ranbaxy Laboratories Ltd has gained a market share in excess if 34% for the drug.

Ranbaxy’s market share is higher than the innovator Novartis’s and its authorized generic partner Sandoz’s.

Novartis, the brand owner of Diovan, has around a 33% market share for the drug even though it lost patent protection in 2012. Sandoz’s generic version has a 32% market share, according to a research report by sector analyst Hitesh Mahida of Antique Stock Broking Ltd.

Ranbaxy got approval for launching the generic version in the US in the first week of July. Although it was to launch the product in September 2012, approval was delayed as the US drug regulator banned the company’s active pharma ingredient unit in India. The company is now sourcing the product from its US factory.

Analysts estimate Ranbaxy’s sales revenue from this product, known as Valsartan in generic terms, at $190 million (Rs1,161 crore) during the first six months, when it has the right to sell the cheaper copy exclusively.

The 180-day exclusivity is an incentive to generic drug makers in the US. This presents a large one-time opportunity, which could contribute revenue of over Rs1,000 crore from a single product—among the largest that Ranbaxy has had in its US sales history.

The generic version of blood thinner drug Lipitor (Pfizer Inc’s blockbuster molecule) was the other top-selling product for Ranbaxy, which had over 50% market share in the US during the exclusivity period.

“We have assumed a 40% average market share with sales and net profit expectations of $190 million and $100 million for Ranbaxy during the 180-days of exclusivity," says Mahida in a report released on Friday.

Diovan was one of the best selling drugs, a so-called blockbuster molecule, for Novartis. The drug contributed at least $3.5 billion in sales for the company in 2013.