The U.S. Food and Drug Administration said this morning it has closed its investigation of Mylan Inc.'s Morgantown, W.Va., generic drug plant and "plans no additional action."

The investigation was prompted by a July 26 Pittsburgh Post-Gazette story citing a Mylan internal report that said workers sidestepped computer-generated warnings about potential problems with the medications they were making. Mylan's report called the quality control breach "pervasive" and "very serious," involving "falsifying information" and "altering product." The breaches, which occurred on all three shifts at the facility, did not affect the quality of any medications, Mylan's report stated.

FDA spokeswoman Judy Leon said this morning Mylan "appears to have conducted an adequate investigation" and that "audit trails were intact for each instance where the software was overridden by the operator."

She said Mylan provided training to operators and was "working with the software company to implement a patch" to fix the problem that allowed employees to bypass the warnings.

Mylan "did not find evidence that the lack of adherence to the [standard operating procedures] resulted in an adverse impact to the affected product lots," the FDA spokeswoman said. "The agency plans no additional action."

Chairman and CEO Robert J. Coury said the FDA's action reaffirms Cecil-based Mylan's "48-year exemplary record of quality."

"Mylan's manufacturing facilities -- especially our plant in Morgantown -- have always represented the gold standard when it comes to quality," Mr. Coury said.

The statement criticized the Post-Gazette for what Mr. Coury called "a highly irresponsible and sensational newspaper article with a biased agenda."

The article "was based on improperly obtained documents, uninformed third-party commentary and anonymous sources," Mylan's statement said.

Mylan did not respond to numerous requests for interviews or respond to a series of questions faxed and e-mailed to its corporate offices for the July 26 story.

The PG's article was based on Mylan's own internal report obtained using proper news-gathering techniques. It also included commentary from multiple experts, including former FDA inspectors, who reviewed the report for the newspaper.

The experts said Mylan's report described "very serious" regulatory violations that raised troubling questions about the integrity and oversight of the plant's quality control operations.

Mylan shares rose on this morning's news. Around noontime, they were trading at $13.99, up 39 cents.