The generic drugs at issue were manufactured at Ranbaxy's facilities in Paonta Sahib and Dewas, India.
Late last year, Pfizer won a victory over one such challenge, from Ranbaxy on Lipitor.
Ranbaxy will face an injunction on launching a generic unless it wins the case on appeal.
Earlier entrants from Merck and Ranbaxy were scrapped because they caused cancer in rodents.
Brothers are largest shareholders in Ranbaxy Laboratories, India's largest pharmaceutical firm in terms of sales.
He's now head of research at Ranbaxy Laboratories in New Delhi, India's largest drugmaker.
Ranbaxy is also codeveloping an antimalarial drug with the Geneva-based nonprofit Medicines for Malaria Venture.
Acquisitions often go wrong, too: Daiichi Sankyo must surely regret paying so much for Ranbaxy.
Almost immediately after Daiichi Sankyo acquired a majority stake in Ranbaxy, problems sprang up.
FORBES: Generic Lipitor Recalled - Another Sign The FDA Needs Help?
For Ranbaxy, the deal removes the risk that it will lose in court.
If Ranbaxy had managed to launch Lipitor early, it stood to make billions of dollars in sales.
Analysts said that with Daiichi now holding a majority 64% stake in Ranbaxy, Singh's departure was inevitable.
As the owner of Ranbaxy, Daiichi Sankyo now shares interests with other foreign makers of generic drugs.
ECONOMIST: Japan's drug firms on the move: A homespun elixir | The
Ranbaxy's chief executive, Arun Sawhney, said earlier this month the company had agreed to settle the matter.
In the worst-case scenario, Ranbaxy would try to hold on to its six-month exclusivity once it was approved.
Ranbaxy had earlier retained former New York City mayor Rudy Giuliani as an adviser on the FDA matter.
Daiichi acquired a majority stake in Ranbaxy, a generic drug maker, in 2008.
Ranbaxy, a generic drugmaker in Gurgaon, India, was looking to make knockoffs, arguing that two Lipitor patents were invalid.
Still, Brian Tempest, who is about to become chief executive, believes Ranbaxy's 700 researchers can help overcome financial constraints.
The rising rupee could help reverse Ranbaxy's currency losses in the next quarter.
If sales of the combo are material at all during that period, Ranbaxy and Pfizer could wind up splitting them for years.
The troubles at Ranbaxy also point to the challenge a foreign drug company has when buying another drug company.
FORBES: Generic Lipitor Recalled - Another Sign The FDA Needs Help?
This is a very tall order, demanding as it does that Ranbaxy produce at least one blockbuster between now and then.
Knockoffs are a good place to start, but Ranbaxy has a higher ambition: to become an innovator in its own right.
Two more patents expire in 2015 and 2017, but analysts expected those would not have kept a Ranbaxy copy of Lipitor off the market.
Ranbaxy would probably have to win both to launch the drug soon.
Meantime, Ranbaxy is hooking up with strong partners--even sometime enemies in court.
In March, for the first time, Ranbaxy had a greater share of the atorvastatin market than Pfizer, according to Fierce Pharma.
FORBES: Atorvastatin Lifts Ranbaxy While Pfizer Abandons Its Lipitor Marketing Efforts
In fact, the quality of this document is emblematic of the problems the FDA has been seeing with Ranbaxy manufacturing plants since 2008.
That year, the FDA raised concerns about adulterated drugs coming into the U.S. from two Indian factories owned by Ranbaxy and opened an investigation.
应用推荐