Propellant-free aerosol formulation for inhalation

A propellant-free solution formulation for inhalation which contain the active substances salbutamol, optionally in the form of the pharmacologically acceptable acid addition salts thereof, and ipratropium bromide and optionally further excipients, in a solvent selected from among water, ethanol and water-ethanol mixtures, the weight ratio of salbutamol to ipratropium bromide being in the range from 5:1 to 5.5:1, a preservative benzalkonium chloride and the solution formulation containing no other active substances, wherein the formulation contains as further constituents one or more complexing agents and wherein a dose of the solution formulation is between about 5 μL and about 25 μL.