A "groundbreaking" injunction has been sought by US authorities against Indian pharmaceutical giant Ranbaxy.
Officials say that the maker of the first generic version of a cholesterol-lowering drug has failed to meet US safety guidelines.
Citing manufacturing and data integrity shortcomings, the Justice Department said US food safety authorities want to block the company from doing business here because its actions made "many of Ranbaxy's drugs adulterated, potentially unsafe and illegal to sell in the United States."
The filing could have a dramatic effect on what was one of the most anticipated rollouts of a generic drug.
The US Food and Drug Administration (FDA) gave the Indian firm the go-ahead last November to make a generic version of Lipitor, which was the best-selling drug of all time and earned US pharma giant Pfizer $100 billion after coming on the market in 1997.
Pfizer's patent on Lipitor -- atorvastatin calcium tablets -- expired at the end of November.
Ranbaxy, which is majority owned by Japan's Daiichi, had faced delays in gaining FDA approval due to problems with quality control at some of its Indian factories.
Those problems came into sharp focus Wednesday with the department's filing, made at the request of the FDA, against India's Ranbaxy Laboratories -- and its subsidiary Ranbaxy Inc, headquartered in Princeton, New Jersey -- in US District Court outside the capital Washington.
"This action against Ranbaxy is groundbreaking in its international reach," Tony West, assistant attorney general for the Justice Department's Civil Division, said in a statement.
"It requires the company to make fundamental changes to its plants in both the United States and India," he added.
"Our commitment to ensuring that the drugs the American people rely on are safe, effective and manufactured according to the FDA's standards extends beyond our borders."
The Justice Department statement listed several problems, including "failure to keep written records showing that drugs had been manufactured properly; failure to investigate evidence indicating that drugs did not meet their specifications... failure to have adequate procedures to prevent contamination of sterile drugs; and inadequate testing of drugs to ensure that they kept their strength and effectiveness until their expiration date."
In addition, "Ranbaxy submitted false data in drug applications to the FDA, including the backdating of tests and the submitting of test data for which no test samples existed," it added.
FDA said it took court action with the Justice Department to protect consumers.
"This company continued to violate current good manufacturing practice regulations and falsify information on drug applications," Dara Corrigan, the FDA's associate commissioner for regulatory affairs, said in a separate statement.
"The FDA continues to be committed to protecting consumers from potentially unsafe products that may be offered on the market."
In the United States, anti-cholesterol drugs account for 255 million prescriptions a year, and about nine million people are taking Lipitor, but sales of the drug reportedly plunged after the introduction of generics.
US-based Watson Pharmaceuticals announced its launch of a generic version of Lipitor under an exclusive supply and distribution agreement with Pfizer, whereby Pfizer manufactures the drug and Watson sells it, sharing net sales with Pfizer until 2016.