Acute oral toxicity and mucosal irritation of a mouthwash containing chlorhexidine and chlorine dioxide in animal models.

BACKGROUND

Halitosis is primarily caused by bacterial activity in the oral cavity. Chlorhexidine (CHX) is a widely used antimicrobial mouthwash but has notable side effects. Chlorine dioxide (ClO2) is a potent oxidizer that may reduce the required CHX concentration while preserving efficacy. This study evaluates the acute systemic toxicity and local mucosal irritation of a CHX-ClO2 combination in animals, to determine its safety for potential human use.

MATERIAL AND METHOD: Mice were administered a single oral dose of a mouthwash containing 0.5 % CHX and 2.5 % ClO2. Clinical signs, mortality, and body weight were monitored over 14 days. In a separate test, rabbit buccal mucosa was exposed to the same mouthwash daily for 14 days. Macroscopic and microscopic irritation scores were recorded according to ISO 10993-23:2021.

RESULT: No mortality or significant clinical toxicity was observed in mice. Only transient ocular irritation occurred in 30 % of the test group.

CONCLUSION

The combination of 0.5 % CHX and 2.5 % ClO2 appears safe in mice and causes negligible irritation in rabbit oral mucosa.