Ninety-nine pints of codeine were seized during a traffic stop along Interstate 10 on Monday, officials say.
According to a news release from the Arizona Department of Public Safety, codeine is commonly used in cold medications, but some people mix it with soft drinks to "obtain a high."
The total value of the seized drugs is estimated around $150,000, the release shows.
Maryland residents Micah Owen-Forney, 22, and Lubre Peeler, 24, were both arrested, the release says. They are facing charges of possession of narcotics, possession of narcotic drugs for sale, transportation of narcotics, and conducting a criminal enterprise.
No further information has been released.