Mallinckrodt Pharmaceuticals, with two plants in north Raleigh, will shut down production for about three weeks this summer and furlough about 30 employees for an additional two weeks, a company spokeswoman said Tuesday.

Mallinckrodt, an Irish company, merged in April with California-based Questcor Pharmaceuticals Inc. in a deal valued at about $5.2 billion. In fiscal 2013, the company was valued at  $2.2 billion, according to the corporate website.

Spokeswoman Lynn Phillips said the shutdown and furlough were in response to market dynamics and customer demand. The furloughs are of employees across the board in Raleigh, but Phillips said other locations in the company, which employs about 5,500 people worldwide, were unaffected.