Gungans & other species
It was first used by the Confederacy of Independent Systems on the Naboo moon/gungan colony of Ohma-D'un. Once there, Commanders Asajj Ventress and Durge deployed it by us enhanced B2 super battle droid armed with swamp gas sprayers. The gas was able to kill the gungan colonists in a matter seconds.
When the Repbulic arrived to investigate the colony's condition and to protect Naboo, Durge and Ventress tried to use the gas on them. Unfortunately, it took longer to kill other species than gungans. However Ventress was able to use her powers of the Dark Side of the force to bring the gungans back to life as zombies to use against the jedi. Unfortunately, the jedi stopped their plans of deploying it on naboo.
The Republic was to recover the cure thanks to Jedi General Kenobi and 4 other jedi. The antidote was on Queyta at the CIS base. Unfortunately, Ventress and Durge fought Kenobi and the jedi for the antidote, but Kenobi alone was able to survive and return to the Jedi Temple with the cure.
Though the Republic was able to study the cure and stop the CIS from using it further, a secret lab on the other side of Queyta was able to move it's equipment to the CIS science vessel Gahenna, where it continued to create more bio weapons, such as Trihexalophine1138.