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Updated: Aug 6, 2026

Intranasal Administration of CNS Therapeutics to Awake Mice
Published on: April 8, 2013
Benzalkonium chloride and nasal mucociliary clearance: a randomized, placebo-controlled, crossover, double-blind
José Angelo Rizzo1, Décio Medeiros, Almerinda Rego Silva
1Research Center in Allergy and Immunology, Clinical Hospital, Federal University of Pernambuco, Recife, Brazil.
Background:
Benzalkonium chloride (BKC) has been considered an innocuous preservative for prescription drugs.
Methods:
We performed a double-blind, placebo-controlled, randomized, crossover, single-center trial with a 3-week washout period in 43 healthy volunteers comparing the effect of 3-week use of saline nasal spray containing BKC 0.01% to preservative-free saline t.i.d. on nasal mucociliary clearance rate. Evaluations were done at the beginning and the end of each period by gamma-scintigraphy with technetium99m-labeled strontium.
Results:
Nasal mucociliary clearance rate was significantly impaired by BKC with a difference of 1.23 mm x min(-1) (p < 0.01) between periods.
Conclusion:
BKC in the concentration used in nasal preparations impaired mucociliary clearance in healthy individuals after 3 weeks of use. Presently, when preservative-free alternatives are available, BKC could be a risk without benefit.
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