The FDA issued a warning to Canadian generic drug maker Apotex last month, citing its Toronto facility for manufacturing problems and alleging use of contaminated ingredients. The letter, the second such warning for an Apotex-run facility in less than a year, includes a tougher compliance measure: restriction of Apotex’s US exports.

Apotex is the company that mounted an at-risk launch of the Bristol-Myers Squibb/Sanofi-Aventis blood thinner Plavix four years ago. The launch came after the firms had failed to settle Apotex’s patent challenge. A federal court ordered Apotex to halt generic sales a few weeks later, but by that time the US market had become filled with Plavix copies—$600 million worth. BMS was also fined after a probe uncovered a side deal a company official had struck with Apotex designed to delay the generic firm’s copycat launch. BMS’s CEO Peter Dolan was subsequently fired. Recently the US Patent and Trade Office ruled to uphold the Plavix patent until 2012.

FDA inspectors checking Apotex’s Toronto facility identified “significant violations” of Current Good Manufacturing Practice (CGMP) regulations, the March 29, 2010 letter states. Investigators also found contamination in equipment at the Toronto facility and said Apotex, which recalled several batches of its products, had been slow to report problems to authorities.

Less than a year ago, Apotex’s Etobicoke, Ontario facility drew a warning letter, also for CGMP violations, found during a December 2008 inspection. The agency issued the letter because, while Apotex said in a written response after the inspection that it had made or had planned to make some needed corrections, it had failed to adequately address “multiple, serious deficiencies,” FDA said.

In the June 2009 letter, FDA said that, until corrections are made, new applications or supplemental approvals made by Apotex could be denied and that failure to correct the violations may result in FDA denying entry of Apotex products into the US.

Following a July/August 2009 inspection, during which FDA found identical violations to those cited in the June 2009 letter, the agency said in August it had put both the Toronto and Etobicoke sites under “Import Alert,” meaning Apotex drugs manufactured at either facility are denied entry into the US.

Among the products manufactured at the two plants are generics of allergy drug Zyrtec, anticonvulsants Klonopin and Topamax, antifungal Nizoral, antibiotic cyclosporine, pain drug Neurontin, neurology drug Depakote and carbidopa-levodopa, used to treat Parkinson’s disease.

FDA issued last month’s warning letter because of “serious and repeat violations” from the 2008 and 2009 inspections.