The company Lupin Pharmaceuticals initiated a recall of more than 2.5 million bottles of eye drops prescribed for inflammation because of the potential presence of a "foreign substance." File Photo by Jim Ruymen/UPI | License Photo

July 9 (UPI) -- The Food and Drug Administration on Thursday recalled more than 2.5 million bottles of eye drops because they may contain a "foreign substance."

The nationwide recall was initiated by Lupin Pharmaceuticals on June 4 because of some type of foreign substance, though the company and the FDA have not identified it or how it got into the eye drops, MassLive and NJ.com reported.

The class II recall of the prednisolone acetate eye drops -- used to reduce inflammation after eye surgery or for allergic and other conditions -- is the second-highest risk recall for the agency because it may cause adverse consequences if used.

In a recall notice posted on its website on Thursday, the FDA said that the recall of more than 2.5 million bottles of Lupin's prednisolone eye drops was because of the "presence of foreign substance."