Today Pfizer won a legal fight over the patent of its top-selling blood-pressure medication, Norvasc. Generic-drug maker Mylan Labortaories challenged the patent on the drug, AKA  amlodipine besylate. A federal judge decided that Pfizer's patent is valid, enforceable and would be infringed by Mylan's proposed drug. Norvasc had $2.5 billion in U.S. sales last year alone. The decision bars Mylan from making a generic version of amlodipine until September. Mylan said it will appeal the judgement(www.Wsj.com). This is another strategy of Pfizer trying to keep their patents valid to boost profits of their best drugs in the market.