CHICAGO, March 11, 2014 /PRNewswire/ -- Medac Pharma, Inc., a privately held pharmaceutical company focused on the development of new molecules and improving the effectiveness of existing medicines, announces the issuance, via its parent company, medac GmbH, of U.S. patent 8,664,231 (the '231 patent) by the United States Patent and Trademark Office. The patent, entitled "Concentrated Methotrexate Solutions," is directed to a method for the treatment of inflammatory autoimmune diseases by subcutaneously administering methotrexate (MTX) at a concentration of more than 30 mg/ml. Medac Pharma and medac GmbH also announce the filing of a lawsuit in the United States District Court in New Jersey against Antares Pharma, Inc. (NASDAQ: ATRS), LEO Pharma A/S and LEO Pharma Inc. for infringement of the '231 patent by their making, selling and offering for sale of Otrexup™ (methotrexate) injection products for treating forms of rheumatoid arthritis, polyarticular idiopathic arthritis and psoriasis. "The grant of the '231 patent in the U.S. is an important step in our ongoing development of MPI-2505, which we believe has the potential to be a best-in-class treatment option for rheumatoid arthritis and psoriasis," said Ms. Terri Shoemaker, President and CEO of Medac Pharma, Inc. "A key advantage to MPI-2505 is its wide range of methotrexate dosing options, which are designed to improve bioavailability and overcome tolerability issues associated with today's oral methotrexate therapies. Providing patients with a ready-to-use autopen for the administration of MPI-2505 in reduced drug volumes also addresses the stigmas associated with injectable medicines. As such, the grant of the '231 patent is a significant event for Medac Pharma, and we and our parent company, medac GmbH, plan to vigorously defend and enforce it." About Medac Pharma, Inc. Medac Pharma, Inc. is the wholly-owned subsidiary of medac GmbH, a well known and respected global pharmaceutical company that has been making scientific and therapeutic discoveries for more than 40 years.