Bacteria Elimination and Virus Neutralization Effects of a CPC-Containing Mouth Spray

Objectives: To assess the effect of a CPC-containing mouth spray eliminating oral bacteria and neutralizing SARS-CoV-2
Methods: A mouth spray containing 0.075% cetylpyridinium chloride was compared to a placebo without CPC for its ability to eliminate oral bacteria both in a short-exposure time kill test and a surface treatment killing test. Monocultures of S. mutans and A. actinomycetemcomitans were treated with the test formulas for 30 s, washed with sterile PBS then plated to determine the reduction in log10 CFUs for each species. Agar plates were coated with whole saliva and treated with the test spray to demonstrate and quantify the elimination of bacteria . Additionally, the spray was tested for inactivation of SARS-CoV-2 using a method based on ASTM E1052.
Results: The test spray resulted in a 4.32 log reduction in viable CFUs of A. actinomycetemcomitans and an 8.62 log reduction in viable CFUs of S. mutans relative to a matched placebo. When a lawn of salivary bacteria was sprayed with the test formula, ~60% of the surface was cleared of viable bacteria. In contrast, the placebo spray cleared <30% of the bacterial lawn, most likely due to physical pressure more than killing. Finally, after 30s contact time, the test spray effectively neutralized >99.44% of an initial load of SARS-CoV-2 virus.
Conclusions: A CPC-containing mouth spray provides a unique means of delivering broad spectrum antimicrobial activity.