"It's a very, very serious violation," Stupak said. "A very, very serious action here. But why did it take over three years?"
But at the FDA, Dr. Douglas Throckmorton, deputy director of the FDA's Center for Drug Evaluation and Research, defended the agency's actions.
"When we first learned about this problem in 2005, we contacted the company, we issued letters to them and we started working with them to correct the manufacturing problems," Throckmorton said. "We continued those inspections, continued those interactions when we had another set of inspections earlier in the year we found deficiencies that required this step."
"I think it's very important for FDA to ramp up its ability to inspect internationally as we import more and more drugs in this country," said Dr. Peter Lurie, deputy director of health research at Public Citizen. "It's good that they are doing it in this case, but the fact is that it's a small fraction of the drugs they can adequately inspect and things can certainly slip through the borders as well."
Still, Lurie said there was "a tension between FDA's statement of seriousness and slow pace at which they have gone after them." He added, "What we're seeing are a series of fairly serious infractions, not keeping production lines separate, not being able to assure that the parts are sterile, not having proper inspection records. All of these are very important if you want to have a truly first-class drug product."
One drug, the antiviral Ganciclovir oral capsules, won't be detained entering the country while problems are being corrected because Ranbaxy is the only company that makes it, the FDA said Tuesday.
The FDA also said that the generics Ranbaxy made in other factories are not problematic. According to Throckmorton, the agency inspected those other facilities and did not find problems. Throckmorton also told consumers on Tuesday "not to discontinue their drug therapy, as such action could seriously jeopardize their health."
ABC News' Brian Hartman and Kate Barrett contributed to this report.
Correction: On our World News piece, we indicated that a generic version of the drug Vytorin came from one of the two Ranbaxy plants. In fact, Vytorin, made by Merck/Schering-Plough, does not have a generic equivalent. Neither of Vytorin's active ingredients are manufactured by Ranbaxy.