BioCorRX’s use of a naltrexone implant for addiction treatment in state prisoners and the homeless was brought into ethical question by a consumer advocacy group in a citizen petition urging the FDA to launch an investigation.

The company only implanted one prisoner with the combination product at the Louisiana Department of Corrections facilities in a trial that was discontinued this spring. The original plan was to include nine more inmates as part of an addiction recovery program.

“BioCorRX and the [Louisiana Department of Public Safety and Corrections] conducted what clearly amounts to a clinical investigation testing a sustained-release naltrexone implant in prison inmates,” according to the Public Citizen petition.