A pharmaceutical formulation, comprising: (a) a compound of formula 1 wherein: R<;SUP>;1 <;/SUP>;is hydrogen, C<;SUB>;1-4<;/SUB>;-alkyl, -O-C<;SUB>;1-4<;/SUB>;-alkyl, or halogen; R<;SUP>;2 <;/SUP>;is hydrogen, C<;SUB>;1-4<;/SUB>;-alkyl, -O-C<;SUB>;1-4<;/SUB>;-alkyl, or halogen; R<;SUP>;3 <;/SUP>;is hydrogen, C<;SUB>;1-4<;/SUB>;-alkyl, -O-C<;SUB>;1-4<;/SUB>;-alkyl, halogen, OH, -O-C<;SUB>;1-4<;/SUB>;-alkylene-COOH, or -O- C<;SUB>;1-4<;/SUB>;-alkylene-COO-C<;SUB>;1-4<;/SUB>;-alkyl; and X<;SUP>;- <;/SUP>;denotes an anion with a single negative charge, or a tautomer, enantiomer, solvate, or hydrate thereof; (b) a second active substance 2 selected from tiotropium salts, oxitropium salts, flutropium salts, ipratropium salts, glycopyrronium salts, and trospium salts, or a tautomer, enantiomer, solvate, or hydrate thereof; (c) at least one pharmacologically acceptable acid; and (d) a solvent selected from water, ethanol, or a mixture of water and ethanol.