Caremark, the pharmacy benefits management business of CVS Caremark Corp., has struggled and reported lower profits in recent years.

Caremark lost several large contracts in 2010, and this year, the company is expected to report a smaller profit because of expenses related to a huge new contract with Aetna Inc. and lower drug prices from a contract with a federal employees' union. The Woonsocket, R.I., company has also faced questions about its business model and scrutiny from regulators. New President and CEO Larry Merlo has said he is committed to the CVS-Caremark combination, and he reiterated that view Thursday in his first earnings call as CEO.

Merlo also said the company has no plans to split up and hit back at "special interests" and other critics. Merlo replaced Thomas Ryan as president in 2010 and became CEO when Ryan officially retired on March 1. Ryan led the company for 16 years and was at the helm in 2007 when CVS, then only a large drugstore chain, acquired Caremark for $26.5 billion.