US FDA approves Impax’s Parkinson’s disease treatment following resolved manufacturing issues

By Zachary Brennan contact

- Last updated on GMT

FDA approves Impax’s Parkinson’s disease treatment

Related tags: New drug application, Food and drug administration

Almost two years since it was first rejected, Impax Pharmaceuticals said late last week that the US FDA has approved Rytary, an extended-release oral capsule formulation of carbidopa-levodopa, for the treatment of Parkinson's disease.

Impax plans to manufacture the treatment out of its Taiwanese facility, which, along with its California facility, has been hampered in the past by quality issues documented by the US FDA.

Impax spokesman Mark Donohue told that Rytary “is linked to the Taiwan facility where it will be manufactured​.”

Regarding manufacturing, we continue to implement a Quality Improvement Program across our facilities.  We submitted responses to the 483’s received this past summer at the Hayward, [California] and Taiwan facilities​,” Donohue said.

We removed Hayward as a backup manufacturing facility from the NDA several years ago, listing Taiwan as the only facility​,” he told us. “Therefore, yesterday’s approval doesn’t speak to any status update regarding Hayward.  We addressed the 483 observations at the Taiwan facility​.”  

Rytary contains immediate release and extended-release beads, with a specific amount of carbidopa and levodopa in a 1:4 ratio, and provides both initial and extended levodopa plasma concentrations after a single dose.


The treatment was initially rejected due to issues at the company’s California manufacturing facility, which in March 2013 was cited in a FDA Form 483​ for 12 observations. Violations included “inadequate​” validation methods performed for the NDA (New Drug Application) for Rytary (levodopa/carbidopa).

Impax later hired a committee of specialists​ to oversee quality improvements at its California facility, and eventually the company settled a lawsuit​ with investors over the manufacturing issues for $8m.

The company then attempted to manufacture Rytary at its Taiwan manufacturing facility, which was hit with a FDA Form 483 in July​. The observations cited in the letter range from improper validation to out-of-specification test results. Specifically the agency took issue with the fact that equipment used to manufacture drugs at the plant is not appropriately validated.

"The FDA approval of Rytary is an important new development for the treatment of Parkinson's disease and provides an extended-release carbidopa-levodopa product that treats Parkinson's disease​," said Fred Wilkinson, president and CEO, who also noted that this is the company’s first branded drug internally developed and approved for commercialization.

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