CORONA, Calif. (AP) — Watson Pharmaceuticals Inc. said Friday it will pay $18 million to Elan Corp. PLC to settle a patent lawsuit over Watson’s generic version of pain reliever Naprelan, or naproxen sodium tablets. Watson also agreed not to marke t or sell its naproxen sodium product until the expiration of the patent on the drug. It did not say when the patent would expire, be found invalid or unenforceable.