Three of the four substances used had never been used for lethal injections - underscoring the difficulty states across America have had in obtaining previously employed execution drugs.
Moore, who received the death penalty after he was found guilty of killing two Omaha taxi drivers, was one of the longest-serving death-row inmates in the US prior to his execution and those close to him said he was ready to die, the Times reported.
Scott Frakes, director of Nebraska's Department of Correctional Services noted in an affidavit that lethal substances "are hard, if almost impossible, to obtain" in many death penalty states. "All we really want is for him to go away".
If the execution occurs Tuesday, it will mark the first lethal injection in Nebraska, which last carried out the death penalty by using the electric chair.
"I recognize that today's execution impacts many people on many levels", said Frakes, adding that the lethal injection was carried out with "professionalism, respect for the process and dignity for all involved".
Nationwide, an increasing number of pharmaceutical companies have taken legal action against states that use their products in executions, making it increasingly hard for states to obtain the drugs.
The Department of Correctional Services said the first lethal injection drug was administered at 10:24 a.m. "I am guilty. They are not", he said.
At one point while on the gurney, Moore turned his head and mouthed several words to his family, including "I love you". But he said there are others on Nebraska's death row who he believes are innocent and he said they should be released.
Smith says Frakes and Acting Warden Robert Madsen waited in the execution room for five minutes to ensure the drugs had taken effect before summoning the county coroner to confirm Carey Dean Moore's death.
"We're sick of hearing about Carey Dean Moore", Steve Helgeland, one of Maynard Helgeland's three children, said ahead of the execution. Nebraska prison officials are preparing to execute Moore on Tuesday, Aug. 14, 2018, for the 1979 murders of two Omaha cab drivers.
"U.S. District Judge Richard Kopf ruled that blocking the execution would 'frustrate the will of the people".
"There was a point in my life when I probably would have pulled the switch myself, but 39 years has a way of dissipating your anger", he said.
Last week, a drug company attempted to stop the execution with a lawsuit alleging the state had illegally obtained its drugs.
But two pharmaceutical companies tried to block the execution in federal court, claiming their reputations would suffer if the killing proceeded. The judge also noted that Moore had stopped fighting the state's efforts to execute him.
A federal appeals court upheld that ruling Monday, and Fresenius Kabi decided not to appeal.
A growing number of states have done away with the death penalty in recent years, including DE, which abolished its use in 2016, and Maryland, which did the same in 2013.