Problem-plagued Ranbaxy Pharmaceuticals Inc. has halted production of a generic version of the cholesterol drug Lipitor while it investigates how tiny glass particles got into the ingredients used for dozens of batches of the drug that were recalled in November. It was Ranbaxy’s second recall of the drug, called atorvastatin, since August.
The Food and Drug Administration said Ranbaxy won’t resume manufacturing atorvastatin until it determines the cause of the latest problem and fixes it. The recall was due to ‘‘possible contamination with very small glass particles similar to the size of a grain of sand,’’ according to the FDA.
‘‘We know that there was glass in the bulk drug ingredient. That’s how it got in,’’ Dr. Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, said.
She could not say whether the bulk ingredient — binders and fillers that are mixed with the active drug ingredient — was produced by Ranbaxy or a contractor.
But Woodcock said the FDA has determined the risk to patients is very low because any glass that ended up in pills would have been pulverized and would be harmlessly excreted.