Rocuronium Bromide Impurity:4-((2S,3S,5S,8R,9S,10S,13S,14S,16S,17R)-17-acetoxy-16-(1-allylpyrrolidin-1-ium-1-yl)-3-hydroxy-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthren-2-yl)morpholine 4-oxide bromide(Rocuronium N-Oxide).