(written from a Production point of view)
Referenced in the first draft script of the Star Trek: Deep Space Nine seventh season episode "When It Rains...", cytromyaline was an explosively volatile chemical. In the script, this substance was referred to as "volatile stuff" by Odo, and Kira Nerys agreed, "A little of it goes a long way."
According to another line of dialogue said by Kira Nerys in the script, Bajoran resistance fighters used cytromyaline to make micro-explosives during the Occupation of Bajor. In the 2375 setting of the scene, Kira had managed to acquire fifty grams of cytromyaline for her and Odo's mission to Cardassia, to assist the Cardassian Liberation Front. Odo commented to her that they would need to be careful with the chemical as they wouldn't be much assistance to anyone if they detonated their own runabout.