Alkermes is working some medicinal alchemy. The firm uses its proprietary drug-delivery systems to make compounds that require less frequent dosing or provide more targeted delivery. Focusing primarily on psychiatric medications, it has a couple of drugs on the market that use its injectable extended-release technology, which lets patients take a drug once or twice a month, rather than once or twice a day. One such drug is Risperdal Consta, a long-acting version of Johnson & Johnson's schizophrenia and bipolar I medication Risperdal. Another is Vivitrol, a treatment for alcohol dependence. Alkermes plc was formed in September 2011 through the merger of US-based Alkermes Inc. and Elan Drug Technologies (EDT).