Fosfomycin preparation
STERILE
In order to obtain fosfomycin solution, the fosfomycin disodium salt was accurately weight and dissolve in distilled water under laminar air flow condition to prepared the 4% (w/v) concentration. The disodium salt of fosfomycin is more appropriate than other salt regarding to it more solubility in order to nebulization. In order to adjust the pH of solution to 7, small amount of HCl were added to the solution. Moreover, the solution was filtered throw 0.1 sterile micrometer to obtained sterile solution. This study employed 2 mL of this solution, which is equal to 80 mg of the medicine, to benefit from the right dose of the medicine. This amount of drug entered the nebulizer jet chamber as a solution and was used by patients. The adjustment of tonicity is not needed as the solution diluted with vapor water during nebulization and does not cause irritation when inhaled. Tobramycin nebulization was performed using 300 mg/5 mL solutions available on the market. This solution was applied after nebulization of fosfomycin.