Abstract: A pharmaceutical composition is disclosed, which contains a short-acting .beta.-blocking compound of the formula ##STR1## wherein R.sub.1 may be an alkyl, cycloalkyl, alkenyl, alkynyl, alkyl carboxymethyl, aryl carboxymethyl, aryl or aralkyl, A may be an alkylene or alkenylene, X may be independently amino, hydrogen, halogen, hydroxy, alkoxy, aryloxy, aralkyl, cyano, amido or trifluoromethyl, n is an integer from 1 to about 4, R may be an alkyl, propargyl, dimethylpropargyl or hydroxyalkyl; or a pharmaceutically acceptable salt thereof in a hydroalcoholic solution further containing a physiologically acceptable buffering agent, ethanol and a physiologically acceptable liquid polyhydric compound. A method for treatment or prophylaxis of cardiac disorders using the composition of the present invention is also disclosed.

Abstract: An injectable, aqueous pharmaceutical composition for the treatment of cardiac conditions comprising an effective amount of methyl 3-[4-(2-hydroxy-3-isopropylamino)propoxy]phenylpropionate hydrochloride (esmolol) for treating such a cardiac condition, said composition comprising about 1 mg to 250 mg of esmolol per milliliter of said injectable pharmaceutical composition; 0.01 to 0.02M buffer; said composition having a pH range of 4.5 to 5.5, the esmolol degrading in aqueous solution to produce 3-[4-(3-propionic acid)phenoxy]-1-isopropylamino-2-propanol hydrochloride, said 3-[4-(3-propionic acid)-phenoxyl]-1-isopropylamino-2-propanol hydrochloride having a pK in the pH range of said composition to thereby act as a secondary buffer to increase the buffer capacity and minimize the change in pH as degradation occurs, whereby the stability of esmolol in an aqueous composition is enhanced.