A federal court jury in the Eastern District of Virginia ruled unanimously that Pfizer did not infringe Synthon IP’s US patent covering a process for making amlodipine, the active ingredient in the blockbuster blood pressure drug Norvasc. Norvasc is the world’s most-prescribed branded medicine for treating hypertension, with $4.7 billion in global sales last year and is Pfizer’s second-best-selling drug behind the cholesterol treatment Lipitor (atorvastatin calcium). “Today’s unanimous decisions underscore our determination to defend our products against unwarranted attacks and to support research-based medical innovations that benefit millions of patients,” said Allen Waxman, Pfizer’s general counsel. Synthon IP is a US subsidiary of Dutch company Synthon BV, which brought its suit against Pfizer in November 2005, asserting that Pfizer infringed a Synthon patent issued in 2003. This patent, Synthon claimed, covered Pfizer’s process for making amlodipine – a process Pfizer claimed to have been using for more than 15 years.