Thanks 3rd, Acl, 235.
My intention was to make the solution isotonic by the addition of 0.9% saline, yes.
Just to clarify, no obfuscation intended.
Below is an abbreviated transcript from a study I recently read called "Safety of a Preservative-Free Acidified Saline Nasal Spray"
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.
Design: Randomized, double-blind, placebocontrolled,
crossover clinical trial.
Setting: Tertiary academic medical center.
Participants: Healthy volunteers with no history or signs
of sinonasal disease.
Interventions: 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.
Main Outcome Measures: 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.
Conclusion: 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.
The Stanford Institutional Review Board approved this study
before enrollment of study participants. We obtained informed
consent from each study participant in compliance with
national patient privacy guidelines.
We recruited 20 healthy adult (18 years) study participants
without a history of sinonasal disease. We excluded individuals
with active or ongoing nasal or sinus symptoms due
to environmental allergies, upper respiratory tract infections,
or sinusitis. We excluded any participant with abnormal nasal
endoscopy findings at the beginning of the study. We excluded
any participants who were pregnant, participants who
were unable to complete the questionnaire for whatever reason,
and participants who were using any medications related
to the treatment of sinonasal disease (eg, antihistamines, decongestants,
and others).
A compounding pharmacy formulated the PFAS (Leiter’s Rx
Compounding, San Jose, California). The PFAS solution contains
0.9% sodium chloride and citric acid, with hydrochloric
acid added to adjust the pH to 2.5. The pharmacist was responsible
for ensuring that the solution was isotonic. We obtained
the BAKS as an over-the-counter product at a local drugstore.
The BAKS is an isotonic solution containing 0.65% sodium chloride,
benzalkonium chloride, phenylcarbinol, disodium phosphate,
and monosodium phosphate (Ocean Spray; Fleming Pharmaceuticals,
Fenton, Missouri). Both solutions are isotonic,
despite their difference in sodium chloride concentration.
The pharmacist placed equal amounts of the 2 test solutions
in identical glass spray atomizer bottles that had equivalent
standardized dispensing volumes. The pharmacist performed
the randomization, thereby masking us, the study
participants, nasal endoscopist, pathologist, and statistician to
the identity of each nasal spray. We unmasked the data only
after completion of the statistical analysis.
Study participants used one coded nasal spray bottle, with
5 sprays in each nostril twice a day for 7 days. This was followed
by a 7-day washout period during which the participants
did not use either of the nasal sprays. Participants then
used the other coded nasal spray bottle, with 5 sprays in each
nostril twice a day for 7 days. We gave the participants an instruction
sheet to remind them of the dosing regimen. Participants
signed an agreement to follow the dosing regimen exactly.
One of us (W.R.R.) telephoned each participant during
each 1-week period of nasal spray use to remind him or her to
continue use of the nasal spray as instructed. Study participants
were permitted to meet with us on the sixth or eighth
day (in lieu of the seventh) if personal scheduling problems so
required. At each follow-up visit, we confirmed in writing the
participant’s adherence to the regimen.
Participants completed 2 symptom questionnaires and underwent
nasal endoscopy at the following 3 time points during
the test period: on enrollment in the study, after 1 week’s
use of the first test bottle, and after 1 week’s use of the second
test bottle. To assess symptoms, we used an 8-symptom visual
analog scale questionnaire and the 20-Item Sino-Nasal Outcome
Test (SNOT-20).15 The visual analog scale assessed the
following symptoms on a scale ranging from 0 (an absence of
symptoms) to 10 (the highest degree of severity) points: nasal
burning, smell disturbance, taste disturbance, nasal bleeding,
purulent rhinorrhea, facial pain, headache, and sore throat. Participants
were asked to rate the mean level of symptoms for the
prior week. The SNOT-20 assessed 10 nasal-related and sinusrelated
symptoms and 10 psychological and behavioral symptoms
on a scale ranging from 0 (an absence of symptoms) to 5
(the highest degree of severity) points. For statistical analysis,
we used the total score and the nasal and sinus symptom subset
score from the SNOT-20 questionnaire.
We scored the nasal endoscopic findings using a modification
of the method by Lund-Kennedy,16 which scores the following
signs from 0 to 2: polyps (0 indicates none; 1, middle
meatus; and 2, beyond middle meatus), discharge (0, none; 1,
clear and thin; and 2, thick and purulent), edema (0, absent;
1, mild; and 2, severe), scarring or adhesions (0, absent; 1, mild;
and 2, severe), and crusting (0, absent; 1, mild; and 2, severe).
We added a score for erythema (0 indicates absent; 1, mild; and
2, severe). For our analysis, we summed the scores for the right
and left nasal cavities for each sign. Therefore, each sign had a
possible score ranging from 0 (an absence of the abnormal sign)
to 4 (the highest degree of severity, bilaterally). For each participant,
we also calculated a total score for all 6 signs. The nasal
endoscopist was unaware of the symptom questionnaire results
at the time of scoring. Each participant received a $20 coffee
coupon card for completing the study.
At the end of each participant’s weeklong trial of each nasal
spray, we obtained a 1-mL aliquot sample from the bottle
under sterile conditions and plated the aliquot on blood and
chocolate agar culture media dishes. The agars underwent incubation
at 37°C for 72 hours at Stanford Hospital Microbiology
Laboratory (a Clinical Laboratory Improvement Act–
certified laboratory), Stanford, California. A pathologist with
microbiological certification (Niaz Banaei, MD, Clinical Microbiology
Laboratory, Stanford University Medical Center),
masked to the type of nasal spray used, then quantified the colonies
of each of 40 sets of blood and chocolate agars for microorganism
growth and identity.
![:\](https://bluelight.org/xf/BL_Images/Orig_Emoji/wrygrin.gif "wry grin :\")
