A fosfomycin plus tobramycin combination formulation for delivery byaerosolization isdescribed. The concentrated fosfomycin tobramycin combination formulationcontaining anefficacious amount of fosfomycin plus tobramycin is able to inhibitsusceptible bacteria.Fosfomycin and tobramycin are formulated separately in a dual ampoule suchthat whenreconstituted, the pH is between 4.5 and 8.0 or as a dry powder. The methodfor treatment ofrespiratory tract infections by a formulation delivered as an aerosol having amass medianaerodynamic diameter predominantly between 1 to 5 µ, produced by a jet orultrasonicnebulizer (or equivalent) or dry powder inhaler.
