The ruling by Judge Kristine Baker of the Eastern District of Arkansas covers nine inmates - six set to die this month, two who had earlier received temporary stays of execution and one whose death had yet to be scheduled.
A USA judge in Little Rock on Saturday temporarily blocked plans by Arkansas to hold a rapid series of executions this month, after the inmates argued the state's rush to the death chamber was unconstitutional and reckless.
The series of legal roadblocks constitute a major setback for Arkansas's Republican governor, Asa Hutchinson, who had pushed for the accelerated executions as the expiration of the state's supply of midazolam drew near. Arkansas was set to execute the first inmate by lethal injection on Monday night.
The courts seem to be lining up to disagree with the governor. Two others won stays of execution from state courts, leaving six of the original petitioners. In addition to the stays granted two men, an Arkansas circuit court judge, Wendell Griffen of Pulaski County, on Friday issued a temporary restraining order barring authorities from using vecuronium bromide, part of a lethal three-drug cocktail the state meant to use.
Arkansas, the company said, bought 10 boxes of vecuronium bromide, which the state can use to stop a prisoner's breathing.
Under the judge's order, Arkansas officials are barred from using one of the three drugs it planned to use in lethal injections, effectively prohibiting them from carrying out the executions as planned.
On Friday, the Arkansas Coalition to Abolish the Death Penalty organized a protest on the steps of the Arkansas State Capitol in Little Rock.
Opponents of the death penalty point to a botched execution in Oklahoma in 2014 which left a prisoner writhing in pain for 40 minutes before he suffered a heart attack as an example why lethal injections should be banned.
Lawyers for all of the convicts have asked a federal court in Little Rock to block the executions, arguing the state's rush to the death chamber was unconstitutional and reckless.
"Without the medical license, and the associated tacit representation that the controlled drug would only be used for a legitimate medical goal, McKesson would not have sold the vecuronium to ADC", the company said in its lawsuit.
In March, Gov. Asa Hutchinson announced his controversial plan to execute eight inmates in a little more than a week, starting April 17.
Drug companies have recently joined the fray, with two manufacturers filing a brief this week arguing that the state had improperly obtained their drugs and planned to use them. The Arkansas Supreme Court issued a stay in his execution.
Arkansas hasn't executed an inmate in more than 11 years because of drug shortages and legal challenges. Griffen scheduled a hearing Tuesday, the day after the first execution was scheduled.
Judge Wendell Griffen granted the temporary restraining order, based on the company's allegations that ADC misled a sales representative to acquire the drug in violation of the company's policy barring sale of drugs for use in lethal injections.
"The unnecessarily compressed execution schedule using the risky drug midazolam denies prisoners their right to be free from the risk of torture", he said in a statement, referring to the drug used to render inmates unconscious before they are given two other drugs that paralyze and kill them.
The lawsuit is among a flurry of challenges the inmates have filed to halt the executions.