A ruling by the Food and Drug Administration means that generic versions of an opioid painkiller made by Endo Pharmaceuticals can stay on the market, drawing criticism from the drug maker.

Purdue Pharma's patent for OxyContin expired Tuesday, opening up the opioid painkiller to generic competition, but authorities have raised concerns about what they call the potential for generic versions to be abused.

Actavis and Mallinckrodt have reached a settlement concerning the former's generic version of an opioid painkiller made by the latter, Actavis said Thursday.

A federal court decision means that a nontamper-resistant formulation of a painkiller made by Endo Health Solutions can enter the market early next month, the drug maker said.

Generic drug maker Watson Labs recalled two lots of a prescription painkiller due to the potential for oversized and overly potent tablets, the company said.

The Food and Drug Administration has approved a new formulation of a painkiller made by Endo Pharmaceuticals designed to thwart drug abuse, Endo said Monday.

Lannett announced that it has started shipping morphine sulfate oral solution, a painkiller approved by the Food and Drug Administration in June.