Scopolamine (AKA Hyoscine) is an anti-cholinergic .The key difference between the salts hydrobromide/butylbromide/methyl nitrate relates to how they behave at the blood brain barrier. Scopolamine butylbromide penetrates poorly, making it useful for its peripheral actions such as for colic and will not cause central effects such as drowsiness. The hydrobromide salt does cross the BBB making it more suited for treating vestibular disorders and nausea; its psychic effects will therefore be more marked than the butylbromide.The methyl nitrate salt also doesnt cross the BBB; this compound is used when researching antidotes to nerve agents, IIRC.
I am paranoid of my brain. It thinks all the time, even when I'm asleep. My thoughts assail me. Murderous lechers they are. Thought is the assassin of thought. Like a man stabbing himself with one hand while the other hand tries to stop the blade. Like an explosion that destroys the detonator. I am paranoid of my brain. It makes me unsettled and ill at ease. Makes me chase my tail, freezes my eyes and shuts me down. Watches me. Eats my head. It destroys me.