U.S. appeals court finds Astra's Seroquel XR patent infringed Thu Feb 14, 2013 8:31pm EST (Reuters) - A U.S. appeals court on Thursday upheld a lower court ruling that found the formulation patent for AstraZeneca's anti-psychotic drug Seroquel XR was valid and had been infringed by Mylan Inc and other companies seeking to sell generic versions of the medicine. Without explanation, the U.S. Court of Appeals for the Federal Circuit in a one-line order affirmed the decision issued by a New Jersey federal court in March. AstraZeneca has said that the judgment is limited to the U.S. market only. The ruling applies to Mylan as well as drugmakers Osmotica Pharmaceutical Corp and Torrent Pharmaceuticals Ltd. Seroquel XR is an extended release version of Seroquel, which is used to treat schizophrenia, bipolar disorder and depression. Facing competition from generic forms of basic Seroquel, AstraZeneca has focused on defending its patents on the long-acting version. AstraZeneca contends that its patent on the extended release version of the drug is valid until 2017. In addition to the United States, the company has previously won Seroquel XR patent challenges in Spain and the Netherlands. British and German courts have found the patent invalid. AstraZeneca welcomed the latest U.S. ruling in a statement, saying it demonstrated the strength of the intellectual property protecting Seroquel XR. Lawyers for the Mylan, Osmotica and Torrent did not immediately respond to requests for comment. The case is AstraZeneca Pharmaceuticals et al v. Anchen Pharmaceuticals et al, U.S. Court of Appeals for the Federal Circuit, Nos. 12-1359. Reporting by Terry Baynes in New York; Editing by Chris Gallagher