Morathial is a drug.
In 2368, Beverly Crusher thought Toby Russell might have used morathial or leporazine on a patient who had died. Russell had used borathium instead. (TNG episode: "Ethics")
In 2371, Julian Bashir planned to treat Bryth with a cycle of morathial and leporazine and thought about using borathium. (DS9 - Deep Space Nine Special comic: "Oaths")