Columbus - A federal appeals court will hear arguments on Tuesday over the constitutionality of Ohio's lethal injection process as the state tries to start carrying out executions once again.At issue is whether a contested sedative, midazolam, is powerful enough to put inmates into a deep state of unconsciousness before two subsequent drugs paralyse them and stop their hearts.A related issue is whether Ohio has a realistic chance of finding an alternative drug - a barbiturate called pentobarbital - that once was widely used in executions, but has become difficult or, in Ohio's case, impossible to obtain.The 6th US Circuit Court of Appeals in Cincinnati scheduled arguments for Tuesday. The court's ruling, likely in a few weeks, will be closely watched not just in Ohio but in other states that use midazolam or might be looking to try it.The case reached the court after Ohio appealed a federal judge's ruling that rejected the state's current three-drug method.Executions have been on hold since January 2014 when inmate Dennis McGuire took 26 minutes to die under a never-before-tried two-drug method that began with midazolam. The same drug was involved in a problematic execution later that year in Arizona.Ohio announced its three-drug method in October, and said it had enough for at least four executions, though records obtained by The Associated Press indicated the supply could cover dozens of procedures.The prison system used 10mg of midazolam on McGuire. The new system calls for 500mg. The state said there's plenty of evidence proving the larger amount will keep inmates from feeling pain.Ohio also said the US Supreme Court upheld the use of midazolam in 2015 in a case out of Oklahoma.Three-drug protocol"Ohio has the capability to perform constitutional executions now. It should be permitted to do so," Thomas Madden, an assistant attorney general, said in Ohio's appeal.Attorneys for death row inmates said Magistrate Judge Michael Merz got it right in last month's ruling, when he said that the "three-drug midazolam protocol creates a substantial risk of serious harm".Those attorneys also said the US Supreme Court case involved evidence unique to Oklahoma. And they said Ohio has an alternative option: finding pentobarbital.Ohio disagrees, and said that over time it asked seven states in vain for the drug. Of the seven, only Georgia, Missouri and Texas appear to have reliable sources of pentobarbital when needed. Those states won't reveal the source.On February 10, Republican Ohio Governor John Kasich delayed eight executions to allow time for the appeals court arguments.Ronald Phillips, who was scheduled to die on February 15 for raping and killing his girlfriend's 3-year-old daughter in Akron in 1993, is now set for execution May 10.