3 hours preferably between 40 minutes and 2 hours more preferably for about one hour to complete the crystallization the crystals obtained are then isolated by filtering or suction filtering to remove the solvent if it should prove necessary to subject the crystals obtained to a further washing step it is advisable to use water or acetone as the washing solvent 0 1 l to 1 0 l preferably 0 2 l to 0 5 l more preferably about 0 3 l of solvent may be used per mole of tiotropium bromide put in in order to wash the tiotropium bromide monohydrate crystals obtained if necessary the washing step may be repeated the product obtained is dried in vacuo or using circulating heated air until a water content of 2 5 to 4 0 is obtained according to one aspect the present invention therefore also relates to formulations of solutions of the type described above using crystalline tiotropium bromide monohydrate which may be obtained by the procedure described above the pharmaceutical formulations containing tiotropium salts according to the invention are preferably used in an inhaler of the kind described hereinbefore in order to produce the propellant free aerosols according to the invention at this point we should once again expressly mention the patent documents described hereinbefore to which reference is hereby made and each of which is incorporated herein by reference in their entireties as described at the beginning a further developed embodiment of the preferred inhaler is disclosed in wo 97 12687 and fig6 thereof this nebulizer respimat u00ae can advantageously be used to produce the inhalable aerosols according to the invention containing a tiotropium.