has split into two parts with a Chicago-based private investment firm purchasing the company’s pharmaceutical development division in Wilmington.

will invest some $75 million in what is now called the AAIPharma Services Corp. It employs some 450 people in Wilmington. The pharma group also includes a chemistry facility in Chapel Hill and a sterile products site in Charleston, S.C.

Not included in the deal is the clinical trials group of AAIPharma, which operates in Morrisville as well as in locations overseas.

"We are thrilled to partner with Water Street to establish ourselves as an independent company," said L. Lee Karras, who was named chief executive officer of AAIPharma Services. He has led that business for three years.

"In addition to providing significant capital resources, Water Street offers extensive pharmaceutical expertise that will benefit our company, employees and customers as we embark on a new strategic course,” he added. “Together with Water Street, we will build on our core strengths to provide our customers with unparalleled knowledge and capabilities that will enable them to successfully navigate the complex drug development process."