Abstract: Almokalant (p-INN), 4-[3-]ethyl[3-(propylsulfinyl)propyl]amino[-2-hydroxypropoxy]-benzonitrile , having the formula ##STR1## is a member of a group of compounds useful in the treatment of cardiac arrhythmias. Enhanced stability, palatability, and technical properties of almokalant can be achieved when it is complexed as a salt with polystyrenesulfonic acid. Accordingly, the invention encompasses the almokalant salt and processes for the preparation of said salt. The invention further encompasses solid oral pharmaceutical dosage forms containing the almokalant-polystyrenesulfonate complex as well as methods for their manufacture as medicaments with action against cadiac arrhythmias.