The "pattern of systemic fraudulent conduct," the government said in court papers filed in Maryland, left an untold portion of the tablets and capsules made by Ranbaxy too weak, too potent or lacking the advertised shelf life. Late last year, Ranbaxy voluntarily recalled 73 million doses of a generic version of Neurontin.
In February 2007, federal agents raided Ranbaxy's North American headquarters in Plainsboro, New Jersey and a manufacturing facility in New Brunswick. The raid was prompted, in part, by problems uncovered in FDA inspections a year earlier at the company's plant in Paonta Sahib, India.
Officials at the plant in northern India fabricated test data to show their pain pills met Food and Drug Administration standards, Star Ledger newspaper reported.
"The government has reason to believe that these violations have resulted and continue to result in the introduction of adulterated and misbranded products" into the United States, federal prosecutors said in court papers, which asked the court to force Ranbaxy to turn over an internal review of its manufacturing operations in India.
The company declined, arguing the report is covered by "attorney-client privilege," the court papers said.
Charles Caprariello, a spokesman for Ranbaxy confirmed the federal investigation.
"We're still working with Food and Drug and the other authorities to resolve any questions," he said. "We've been conscientious in trying to provide information to the government.
"At this point in time, we're conducting business as normal until we address these questions."
The investigation was disclosed in a motion filed July 3 in U.S. District Court in Maryland just days after the Japanese drugmaker Daaichi Sankyo announced plans to acquire a majority stake in Ranbaxy. The merged company would have a combined market value of about $30 billion.
Ranbaxy manufactures medicines in 11 countries to treat high cholesterol, hypertension, infections, seizures and other maladies. The company also received funding under a special Bush administration initiative to manufacture low-cost generic HIV/AIDS medication for distribution in Africa.
One of the world's largest generic drugmakers, Ranbaxy had global sales of $1.5 billion last year, including $390 million in the United States.
The probe of Ranbaxy highlights growing concerns about the production and regulation of generic drugs, which are supposed to have the same active ingredients as the brand-name medicines they copy and meet FDA standards for strength, purity and quality.
The allegations against the company are reminiscent of the 2005 case of Able Laboratories, a defunct Cranbury-based drugmaker that went belly up after FDA uncovered a wide-ranging conspiracy to sell medicines that did not meet federal standards. It prompted one of the biggest recalls in American pharmaceutical history and resulted in guilty pleas by a half-dozen company officials.