Synthon Pharmaceuticals Ltd of Chapel Hill says it has received U.S. Federal Food and Drug administration approval to market it’s cheaper alternative to GlaxoSmithKline’s anti-depression drug Paxil.

The FDA approved Synthon’s Paroxetine Mesylate as an alternative for patients treated for depression, obsessive/compulsive disorder or panic disorder by a serotonin reuptake inhibitor such as Paxil.

Serotonin is a brain chemical that helps improve mood and reuptake inhibitors such as Paxil help keep it in the brain longer. Last year, Synthon says, US consumers and insurers paid $2 billion in the paroxetine therapy market.

Synthon says its formulation will cost 30-40 percent less than the $3 a pill for Paxil, but its safety and efficacy profile is similar to the more expensive drug.

“Competition and choice bring savings,” Synthon president William Taylor says, “and those savings will allow patients, payers and governments to stretch limited healthcare resources as far as possible.”

Synthon spokesman Greg Howard tells Local Tech Wire that GSK has accused Synthon of infringing its Paxil patents in court. Synthon has asked the US District Court for the Middle District of North Carolina for summary judgment to dismiss the GSK suit.

A hearing was held 45 days ago. “We feel comfortable that once the court looks at all the facts it will rule in our favor,” Howard says.

He adds that Synthon, which is owned by Synthon Holdings based in the Netherlands, expects to have its product on the market by the fourth quarter this year or sooner.

Howard says the company is working on a “wide array of generic drugs and branded products.”

Synthon employs 25 people in Chapel Hill.