The former head pharmacist at a major Manhattan hospital was charged on Tuesday with stealing about 200,000 oxycodone pills — with a street value of $5.6 million — by requisitioning them from his own pharmacy for phantom research projects, New York City's special narcotics prosecutor said. The pharmacist, Anthony D'Alessandro, began stealing the pills in early 2009 from the hospital, Mount Sinai Beth Israel, then known as Beth Israel Medical Center, and continued taking them in escalating quantities, even after he was reported to hospital officials by an anonymous tip, the prosecutor, Bridget G. Brennan, said. The tip came in a letter to the president of Mount Sinai Health System, which merged with Beth Israel's parent company last year. Computerized records of oxycodone requisitions, including the date, time and quantity, accompanied the letter.