Mylan Inc. said Friday it is immediately launching a generic version of the Alzheimer''s disease drug Razadyne after receiving regulatory approval and a favorable court ruling, according to the Associated Press. The original drug is made by Ortho-McNeil Neurologics, a unit of Johnson & Johnson. Razadyne is designed to treat mild to moderate dementia associated with Alzheimer''s disease. On Thursday, the U.S. District Court for the District of Delaware voided one of the patents behind Razadyne and Razadyne ER, paving the way for the introduction of generic versions. Mylan said the Food and Drug Administration then approved its application for generic Razadyne, allowing it to start selling 4 milligram, 8 milligram and 12 milligram tablets. Rival Barr Pharmaceuticals Inc. received FDA approval Thursday and immediately launched its version. The companies are among a group sharing 180-day marketing exclusivity, meaning only those companies will be able to sell Razadyne and Razadyne ER over the next six months. Mylan''s version will be made by its Alphapharm Pty Ltd. subsidiary, and marketed by Mylan Pharmaceuticals.