A fosfomycin plus tobramycin combination formulation for delivery by aerosolization is described. The concentrated fosfomycin tobramycin combination formulation containing an efficacious amount of fosfomycin plus tobramycin is able to inhibit susceptible bacteria. Fosfomycin and tobramycin are formulated separately in a dual ampoule such that when reconstituted, the pH is between 4.5 and 8.0 or as a dry powder. The method for treatment of respiratory tract infections by a formulation delivered as an aerosol having mass median aerodynamic diameter predominantly between 1 to 5 μ, prod ed by a jet or ultrasonic nebulizer (or equivalent) or dry powder inhaler.本發明闡述一種藉由噴霧化輸送的磷黴素(fosfomycin)加妥布黴素(tobramycin)組合調配物。該含有有效量之磷黴素加妥布黴素之濃縮磷黴素妥布黴素組合調配物能抑制敏感細菌。磷黴素及妥布黴素單獨調配於一雙安瓿中以使得當重配之時，pH介於4.5與8.0之間，或調配為乾粉。本發明亦闡述一種藉由以噴霧(主要具有1至5微米之質量平均空氣動力直徑)輸送之調配物來治療呼吸道感染之方法，該噴霧係藉由一噴氣式噴霧器或超音噴霧器(或等效物)或乾粉吸入器產生。
