There is described a mixture of 4-[2-(6-(2-phenylethylamino)hexylamino)ethyl]-1,2-benzenediol, or 4-[2-(6-(2-chlorophenyl)ethylamino)hexylamino)ethyl]-1,2-benzenediol or a pharmaceutically acceptable acid addition salt of either thereof or as active ingredient, and a physiologically acceptable acid. There is also described a method of preparing a solid form of the active ingredient, which comprises freeze drying an aqueous solution of the mixture, and a freeze dried composition containing the active ingredient prepared by the method. The mixtures are useful as pharmaceuticals, e.g. in the treatment of cardiovascular conditions.

Compounds of the formula I in which R.sub.1 is unsubstituted or substituted phenyl, R.sub.2 is hydrogen lower alkyl, unsubstituted or substituted phenyl or free or esterified carboxy, and in which R.sub.3 is hydrogen or lower alkyl and R.sub.4 is a group of the formula --alk.sub.1 --X--alk.sub.2 --R.sub.5, or R.sub.3 and R.sub.4 together are a group of the formula --alk.sub.3 --NH--alk.sub.4 --, alk.sub.1 and alk.sub.2 being lower alkylidene, alk.sub.3 and alk.sub.4 lower alkylene, X a direct bond, methylene or unsubstituted or substituted phenylene and R.sub.5 being hydroxy, amino or substituted amino of the formula --N(R.sub.6)--CH(R.sub.7)--R.sub.8 in which R.sub.6 is hydrogen, or, provided that R.sub.3 is hydrogen, it may alternatively be lower alkyl or unsubstituted or substituted phenyl-lower alkyl, R.sub.7 is hydrogen, lower alkyl, unsubstituted or substituted phenyl or free or esterified carboxy and R.sub.8 is unsubstituted or substituted phenyl, and their pharmaceutically acceptable salts have properties that ease breathing and are suitable for combating respiratory disorders, preferably as active ingredients in and/or for the manufacture of pharmaceutical preparations that ease breathing.