2-propan-2-yloxyethyl 4-[2-hydroxy-3-(propan-2-ylamino)propoxy]benzoate; 2-Isopropoxyethyl 4-[[(2RS)-2-hydroxy-3-(isopropylamino)propyl]oxy]benzoate; Keto Bisoprolol; 4-[2-Hydroxy-3-[(1-methylethyl)amino]propoxy]-benzoic acid 2-(1-methylethoxy)ethyl Ester; 2-Isopropoxyethyl 4-(2-hydroxy-3-(isopropylamino)propoxy)benzoate; 2-Isopropoxyethyl-4-[[(2RS)-2-hydroxy-3-(isopropylamino)propyl]oxy]benzoate; Bisoprolol Ester Impurity; 2-Isopropoxyethyl 4-[2-hydroxy-3-(isopropylamino)propoxy]benzoate; Bisoprolol Related Compound F (USP)