DUBLIN (AP) -- Shares of Mallinckrodt slid 12 percent Tuesday after the Irish drugmaker reported disappointing quarterly revenue and said growth in sales of its HP Acthar Gel, the target of a $5.6 billion acquisition last year, may be lower than it expected. HP Acthar Gel is taken from the pituitary glands of pigs after the animals are slaughtered, and it's used to treat a variety of autoimmune and inflammatory conditions including infantile spasms, eye inflammation and rare skin diseases. In August, Mallinckrodt bought Questcor Pharmaceuticals, the company that markets Acthar, for $5.6 billion. It said the drug was a crucial asset, the foundation of its broad autoimmune and rare disease business. The company reported $269 million in Acthar revenue in its fiscal third quarter, and the drug was by far its... More