Updated

Texas prison officials say they're using a compounding pharmacy to obtain the drug used during executions.

The Texas Department of Criminal Justice, responding to a Freedom of Information request from The Associated Press, disclosed Wednesday that it purchased eight vials of pentobarbital last month from a compounding pharmacy in suburban Houston.

Such pharmacies custom-make drugs and aren't subject to federal scrutiny.

Texas' previous supply of the sedative expired last month, and prison officials had refused to say where they were getting their new supply.

Department spokesman Jason Clark says Texas, the nation's most active death-penalty state, now has enough to carry out scheduled executions into next year.

Three death-row inmates have filed a lawsuit, saying Texas will use untested execution drugs. They say that amounts to cruel and unusual punishment.