In a double-blind controlled study , 27 patients with an established diagnosis of CF and a documented nasal infection with Pseudomonas aeruginosa and/or Staphylococcus aureus [ 22 males ( 81 % ) , median age of 15 years ( range 5-26 yrs ) ] , were randomized to receive the nasal spray formulation containing hyaluronate and tobramycin ( N = 14 ) or hyaluronate alone ( N = 13 ) for 14 days .