The invention relates to a method for producing a micronized, virtually anhydrous form of (1α,2β,4β,5α,7β)-7-[(hydroxydi-2-thienylacetyl)oxy]-9,9-dimethyl-3-oxa-9-azoniatricyclo[3.3.1.02,4]nonane bromide, said form per se, and the use thereof for producing a medicament, especially a medicament having an anticholinergic effect.