Pyridinium,1-[[4-[[[[3-[3,3-dibutyl-7-(dimethylamino)-2,3,4,5-tetrahydro-1,1-dioxido-1,4-benzothiazepin-5-yl]phenyl]amino]thioxomethyl]amino]phenyl]methyl]-4-(1-ethylpropyl)-, bromide