KNOXZY Sterile Isotonic Saline Solution 0.9% - Sodium Chloride NaCl - Inhalation Saline Solution for Humidifying The Airways. This solution works effectively for the improvement of respiratory tract function. It is preservative-free and comes with 20 single-use pre-measured 2.5ml containers. How To Use: Depending on the need, up to four vials per day can be used. Break off container and open it by twisting off the top.