title: Safety of a preservative-free acidified saline nasal spray: a randomized, double-blind, placebo-controlled, crossover clinical trial.
abstract: OBJECTIVE
  To determine the safety and tolerance of a buffered preservative-free acidified solution as an alternative to standard chemical preservatives to prevent microbial contamination of saline nasal spray.
  
  
  METHODS
  Randomized, double-blind, placebo-controlled, crossover clinical trial.
  
  
  METHODS
  Tertiary academic medical center.
  
  
  METHODS
  Healthy volunteers with no history or signs of sinonasal disease.
  
  
  METHODS
  Twenty volunteers used a buffered preservative-free acidified solution in a saline nasal spray and a benzalkonium chloride-containing saline nasal spray for 1 week each, separated by a 1-week washout period.
  
  
  METHODS
  At study enrollment and after using each nasal spray solution, participants completed a visual analog scale symptom questionnaire and the 20-Item Sino-Nasal Outcome Test and underwent nasal endoscopic examination, which was graded using a modified Lund-Kennedy scoring system. At the end of each test period, the contents of each nasal spray bottle were cultured for microorganism growth.
  
  
  RESULTS
  All 20 participants completed the study. Four participants who developed upper respiratory tract illnesses during the study period were excluded from secondary analyses. No differences were observed in specific sinonasal symptoms or nasal endoscopy findings after use of either nasal spray. No nasal spray solutions from either group had any microorganism growth.
  
  
  CONCLUSIONS
  In a short-term study with a small sample size, a preservative-free acidified solution seems to be safe and well tolerated, while maintaining sterility in a multiple-dose applicator without use of chemical preservatives.
authors.affiliation: Division of Rhinology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA. williamryan75@gmail.com
authors.forename: William R
authors.initials: WR
authors.lastname: Ryan
authors.forename: Peter H
authors.initials: PH
authors.lastname: Hwang
mesh_terms: D000281:Administration, Intranasal; D000328:Adult; D000704:Analysis of Variance; D001548:Benzalkonium Compounds / Q000008:administration & dosage; D001592:Benzyl Alcohols / Q000008:administration & dosage; D019343:Citric Acid / Q000008:administration & dosage; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004724:Endoscopy; D005260:Female; D006801:Humans; D006851:Hydrochloric Acid / Q000008:administration & dosage; D008297:Male; D010919:Placebos; D011310:Preservatives, Pharmaceutical / Q000008:administration & dosage; D012965:Sodium Chloride / Q000008:administration & dosage*; D011795:Surveys and Questionnaires
chemical_list: D001548:Benzalkonium Compounds; D001592:Benzyl Alcohols; D010919:Placebos; D011310:Preservatives, Pharmaceutical; D019343:Citric Acid; D012965:Sodium Chloride; D006851:Hydrochloric Acid