– Georgia postponed its first execution of a woman in 70 years late Monday, as officials cited problems with the lone drug that would be used for the lethal injection.

The drug, pentobarbital, had a cloudy appearance, prompting officials to call a pharmacist and then out of an "abundance of caution" to postpone the execution, said Georgia Department of Corrections spokeswoman Gwendolyn Hogan. She did not give a new date.

Kelly Renee Gissendaner was scheduled to be executed at 7 p.m. at the prison in Jackson. The execution was put on hold while officials waited for the U.S. Supreme Court to either grant or deny a stay requested by her lawyers. The court had still not ruled more than four hours later.

An appellate court rejected the lawyers' request for a delay on the grounds that Georgia's lethal-injection procedures aren't transparent enough to be challenged in court. Late Monday, the lawyers added additional arguments for the high court: that it should consider a stay because Gissendaner didn't kill her husband, Douglas Gissendaner, herself in February 1997. They also argued that she had been thoroughly rehabilitated.

Previously, courts had found Gissendaner had plotted the stabbing death of her husband by her boyfriend, Gregory Owen, who will be up for parole in eight years after accepting a life sentence and testifying against her.

Gissendaner would be only the 16th woman put to death nationwide since the Supreme Court allowed the death penalty to resume in 1976. About 1,400 men have been executed since then, according to the Death Penalty Information Center.

The Georgia Board of Pardons and Paroles, the only entity authorized to commute a death sentence, denied clemency last week and upheld that decision late Monday.

Associated Press