Hyoscine butylbromide Imp F (EP): (1R,2R,4S,5S,7s,9s)-9-butyl-7-[[(2 S)-3-hydroxy-2-phenylpropanoyl]oxy]-9-methyl-3-oxa-9-azoniatricyclo[3.3.1.02,4]nonane (pseudo-isomer).