A novel polymorphic crystal form of (R)-3-(2-hydroxy-2,2-diphenyl-acetoxy)-1-(isoxazol-3-ylcarbamoyl-methyl)-1-azonia-bicyclo-[2.2.2]octane bromide, designated crystal form Talpha. Methods for preparing same and the use of the crystal form as the active ingredient of medicaments for the treatment of inflammatory or obstructive airways diseases are also described.