Christopher Peters is charged with possession of a controlled dangerous substance on school property.
Supervising assistant Ocean County Prosecutor Michael Paulhus said the 56-year-old Peters purchased Roxicet from a Little Egg Harbor Township man at Pinelands Regional High School Thursday.
He went on to allege that the purchase happened during the school day.
Roxicet is a combination of acetaminophen and oxycodone.
Police also arrested the other man, identified as Mark Kilmurray, age 31, of Little Egg Harbor Township.
Peters' bail was set at $10,000. Kilmurray's bail was set at $40,000.
Peters worked at Pinelands for more than 30 years.
The school superintendent declined to go on camera, saying this was a police matter and they were handling it.
However, the superintendent did issue a statement saying "the district and the board of education has been, and will continue to be, proactive in finding and addressing any misconduct as quickly and as seriously as we are allowed to by law."
Anyone with information relative to this investigation is asked to contact Patrolman Joel Mahr of the Little Egg Harbor Township Police Department at (609) 296-3666 extension 178.