Abstract: The present invention relates to dried preparations containing a class III antiarrhythmic compound in the form of a crystalline or amorphous salt or any combination thereof, where the counterion is selected from pharmaceutically acceptable water-soluble organic or inorganic acids. The present invention also relates to frozen preparations containing a class III antiarrhythmic compound in the form of a salt solution, where the counterion is selected from pharmaceutically acceptable water-soluble organic or inorganic acids. Preferred preparations contain a salt of the compound 3,7-diazabicyclo[3.3.1]-nonane-3-carboxylic acid, 7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-1,1-dimethylethyl ester (Compound A). Further aspects of the present invention include salts of Compound A per se, processes for preparing the preparations, as well as use of the preparations for prophylaxis and/or treatment of cardiac arrhytmia.