TOBI® is an antibiotic solution that is breathed (inhaled) into the lungs. TOBI® is helpful in fighting lung infections, reducing the number of days in the hospital, and improving lung function. TOBI® is a clear to light yellow solution. It comes in a sterile, single-dose plastic vial holding 300mg in 5ml of fluid. TOBI® should be refrigerated and protected from the light. However, if you don’t refrigerate it, the color may darken, but it is still safe to use. If the medicine looks cloudy, has particles floating in it, or has been sitting out for more than 28 days, throw it away.