Mpex Pharmaceuticals developed inhaled levofloxacin (brand name Quinsair), an antibiotic used for long-term lung infection treatment in people with cystic fibrosis. Levofloxacin is a well-known antibiotic that had been approved and prescribed for treating infection via infusion and oral administration since the 1990s.

Acquired in September 2011, now commercialized by Horizon Pharma.