KANSAS CITY, Mo. (AP) – Missouri is appealing a federal court’s decision that requires the state to break one of its most-guarded secrets and reveal the name of any supplier of its lethal injection drug.

Calling the matter “a question of exceptional importance,” the state on Wednesday asked the full 8th Circuit Court of Appeals to urgently upend a ruling last week by a three-judge panel of that court in a case brought by two death-row inmates in Mississippi.

The court rejected Missouri’s claim that disclosing its source of pentobarbital could compromise its ability to obtain the drug for executions.

The inmates question why Mississippi doesn’t adopt a one-drug execution method as Missouri has done. They’ve subpoenaed Missouri for details about pentobarbital to meet their legal burden of showing there’s a known, available alternative.