Effect of Mouthwash in Reducing the Symptoms Associated With Flu and Cold Viruses

Efficacy of Cetylpyridinium Chloride and Zinc Mouthwash in Reducing the Occurrence of Symptoms Associated With the Flu and Cold Season - a Randomized Clinical Trial

The aim of this study will be to evaluate the efficacy of regular cleaning of the oropharynx (via gargling) on the incidence of symptoms associated with flu and colds. The working hypothesis is that there will be a significant reduction in symptoms associated with flu and colds after using the mouthwash product, compared to the experimental control regime. A total of 150 individuals will be randomized to one of the two experimental regimens and followed for a period of 90 days. The experimental regimen consists of toothbrushing followed by gargling with a cetylpyridinium chloride (CPC) (0.075%) and zinc containing alcohol free rinse and the control regimen consists of toothbrushing alone. Participants will be instructed to brush their teeth twice a day for two minutes. Those allocated to the test regime will gargle with 20 ml of the mouthwash after each brushing. At the initial visit, participants will receive the products and instructions for use, as well as a daily log questionnaire. Participants will be asked to send their daily records once a week, using a messaging application. The proportion of days without any of the evaluated symptoms will be used as the main outcome. In addition, soft and hard tissue exams will be performed at the initial consultation, after 30 and 90 days of follow-up by a blinded researcher. Potential adverse events will be collected throughout the study. The groups will be compared using the chi-square test and one-way analysis of variance (ANOVA) will be used to compare the treatment group symptom rates between groups. The significance level will be set at 95%.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Drug: cetylpyridinium chloride (0.075%) and zinc alcohol free mouthwash

• Study Type: Interventional
• Enrollment (Actual): 150
• Phase: Phase 3

Contacts and Locations

Study Locations

• Brazil
  • Rio Grande do Sul
    • Pelotas, Rio Grande do Sul, Brazil
      • Federal University of Pelotas

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Good systemic general health as determined by study investigators; Availability of 90 days to participate in the study;

Exclusion Criteria:

• those participating in any other clinical study;
• Pregnant or breastfeeding;
• Presence a history of allergies to oral hygiene products, personal hygiene products, or their ingredients;
• Have mouth irritation or use oral anesthetic sprays;
• Have diabetes;
• Be undergoing extensive dental treatment or oral surgery during the study;
• Present immunocompromised (HIV, AIDS, immunosuppressive drug therapy);
• Use complete dentures;
• Do not have carpal tunnel syndrome or arthritis in the hands.
• Participant who substantially fails to follow the required protocols;
• Participant who fails to attend scheduled appointments;
• Participant who is treated, during the study period, with medications that may interfere with the parameters being analyzed in the study;
• Participant who is treated by a medical or dental service, and this may interfere with the parameters being analyzed in the study;
• Participant who develops serious adverse reactions.
• The participant who chooses to terminate their participation in the study;
• Participant reports being pregnant during the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control; Toothbrushing alone
Experimental: cetylpyridinium chloride (0.075%) and zinc alcohol free mouthwash; Toothbrushing + mouthrinse	Drug: cetylpyridinium chloride (0.075%) and zinc alcohol free mouthwash; mouthrinse

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Upper Respiratory Symptom	any upper respiratory system associated with colds and flu according to the Wisconsin Upper Respiratory Symptom Survey (WURSS-21) Daily Symptom Report.	90 days

Collaborators and Investigators

• Sponsor: Colgate Palmolive

Publications and helpful links

General Publications

• Muniz FWMG, Casarin M, Pola NM, Rosing CK, Silveira TMD, Silva FH, de Holanda GA, de Oliveira LV, Dantas PPA, Stewart B, Malheiros Z, Benitez C, Schaeffer L. Efficacy of regular gargling with a cetylpyridinium chloride plus zinc containing mouthwash can reduce upper respiratory symptoms. PLoS One. 2025 Feb 26;20(2):e0316807. doi: 10.1371/journal.pone.0316807. eCollection 2025.

Study record dates

Study Major Dates

• Study Start (Actual): June 5, 2022
• Primary Completion (Actual): October 6, 2022
• Study Completion (Actual): October 6, 2022

Study Registration Dates

• First Submitted: June 24, 2024
• First Submitted That Met QC Criteria: June 24, 2024
• First Posted (Actual): June 28, 2024

Study Record Updates

• Last Update Posted (Actual): March 18, 2026
• Last Update Submitted That Met QC Criteria: March 16, 2026
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Organic Chemicals; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Inorganic Chemicals; Elements; Metals; Alcohols; Metals, Heavy; Transition Elements; Pyridinium Compounds; Ethanol; Zinc; Cetylpyridinium
• Other Study ID Numbers: CRO-2022-04-FLU-REG-BZ-ZM

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No