SUNSTAR research suggests CPC-containing mouthwash could help reducing the SARS- CoV-2 viral load by more than 99.9% in vitro.

07 June 2021

For Europe, Middle-East and Africa countries only

New in vitro test results show that within 30 seconds of exposure, mouthwash containing CPC (Cetylpyridinium Chloride) reduces the SARS- CoV-2 viral load by 99.9% following ASTM International standard E1052-20 on Standard Practice to Assess the Activity of Microbicides against Viruses in Suspension.

This new in vitro test was conducted at the request of Sunstar Inc. and Sunstar Suisse SA by a third party testing organization QTEC Services in Tokyo Japan to evaluate the reduction in viral load following exposure to certain mouthwashes containing CPC. SARS-CoV-2 in suspension was exposed during 30 seconds to multiple formulations including 0.04% to 0.3% of CPC. The results show SARS-CoV-2 load was reduced by over 99.9%.

The preliminary test results corroborate the work previously done which shows CPC reduces the SARS-CoV-2 viral load. This suggests the use of mouthwashes containing CPC could be an additional measure to reduce viral transmission of SARS-CoV-2. Of course those preliminary in vitro data need further investigations and we will explore its potential.
Dr Tsutomu Takatsuka, Senior Executive Officer, Global R&D at Sunstar

The global scientific community embraces a growing body of evidence suggesting the use of mouthwash containing CPC can inactivate the virus and become an important additional measure to reduce the transmission of SARS-COV-2, but also emphasizes that people should continue to follow the preventive measures. There is no evidence that mouthwash protects against getting infected with coronavirus, so all preventive measures including hand sanitizing, social distancing and consistent mask use should be implemented.

Sunstar also welcomes the addition of pre-procedural rinses containing CPC to the dental care routine as it lowers the viral load of patients before and during treatment. As Dr Takatsuka, explains: “using mouthwashes with CPC as a pre-procedural rinse at the dental practice should be considered.” The routine use of ultrasonic scalers, dental and surgical instruments can create visible spray – water, saliva, blood, that can contain the SARS- CoV-2 and help spread the virus at the dental practice.

How can CPC inactivate SARS-CoV-2?

Mouthwash containing CPC has been shown to inactivate SARS-CoV-2 within 30 seconds of exposure 1,2 through its ability to disrupt the viruses’ protective membrane 3,4 Coronaviruses including SARS- CoV-2 are surrounded by a lipid membrane or “envelope” which contains the spike glycoprotein responsible for the infection.

Even though the oral cavity is not likely to be the main route of infection for the SARS- CoV-2, ACE2, the main receptor responsible for entry of SARS-CoV-2 into host cells, is expressed on epithelial cells of the oral mucosa, which means that the virus is able to colonize the oral cavity. In essence, the presence of ACE2 in the mouth allows the virus to enter cells and cause infection5.

The use of a mouthrinse containing CPC is the most evidence-based way to control cross infections in the dental office while maintaining all safety measures including hand disinfection, social distancing and mask wearing. Compared to the use of H2O2 (Hydrogen Peroxide) we know CPC can have a sustained effect for some hours that could guarantee the protective action during the treatment. 6-9

We already have mouthwashes containing CPC available and know they are effective and well tolerated. We welcome having one product for pre- and post-treatment

Professor Magda Mensi, of the Periodontology Department of the University of Brescia in Italy

Sunstar test results corroborate the work done in the UK and Singapore. Early results in COVID-19 patients suggest the effect of mouthwash containing CPC could last up to 6 hours

At Cardiff University’s Immunity Research Institute, a report explains that researchers tested the in vitro effectiveness of a handful of mouthwashes at reducing SARS-CoV-2 and found that CPC-containing mouthwashes inactivated the virus below the detection limit.1

At National Dental Research Institute Singapore (NDRIS), Dr Seneviratne and colleagues went a step further and demonstrated that the effect of mouthwash containing CPC was sustained 6 hours after mouthrinse use in COVID-19 patients.

Researchers in Singapore undertook the first randomized clinical study to examine the efficacy of commercial mouthrinses containing CPC on SARS-CoV-2 in COVID-19 patients 2. The study, showed that CPC-containing mouthrinse can suppress the salivary SARS-CoV-2 levels within 5 minutes of use, compared to water rinsing, and that this effect persists 6 hours after rinsing.

Drs Seneviratne and Sim Xiang Ying at the National Dental Research Institute Singapore commented in their study report that “mouth-rinses could play a vital role in minimizing the spread of SARS-CoV-2 with its use as a pre-procedural strategy in dental clinics.”

Sunstar will keep promoting research and raising scientific awareness which may ultimately help enhance the quality of life of people everywhere.

  1. O’Donnell VB, Thomas D, Stanton R, et al. Potential Role of Oral Rinses Targeting the Viral Lipid Envelope in SARS-CoV-2 Infection. Function 2020; 1.10.1093/function/zqaa002
  2. This study has not yet been peer-reviewed or published in a scientific journal but is available on a preprint server for health sciences Seneviratne Chaminda J., Sim Xiang Ying J. et al “Efficacy of commercial mouth-rinses on SARS-CoV-2 viral load in saliva: Randomized Control Trial in Singapore” medRxiv preprint ; September 18, 2020.
  3. Evelina Statkute, Richard Stanton et al ”Brief Report: The Virucidal Efficacy of Oral Rinse Components Against SARS-CoV-2 In Vitro” bioRxiv preprint, November 13,
  4. Popkin DL, Zikka S, Dimaano M, et al., Cetylpyridinium Chloride (CPC) Exhibits Potent, Rapid Activity Against Influenza Viruses in vitro and in vivo, Pathog. Immun., 2017 (2) 252-269
  5. Xu Hao, Zhong Liang et al « High expression of ACE2 receptor of 2019-nCoV on the epithelial cells of oral mucosa” International Journal of Oral Science, 24 Feb 2020.
  6. Daniel H. Fine, Carlos Mendieta, Michael L. Barnett,f David Furgang, Ronnie Meyers, Arnold Olshan,f and Jack Vincent, Efficacy of Preprocedural Rinsing With an Antiseptic in Reducing Viable Bacteria in Dental Aerosols, Journal of Periodontology, Vol 63,
  7. Issue 10, October 1992
  8. Vanessa Costa Marui, DDS; Maria Luisa Silveira Souto, DDS; Emanuel Silva Rovai, DDS, Giuseppe Alexandre Romito, PhD, MSc, DDS; Leandro Chambrone, PhD, MSc, DDS, Claudio Mendes Pannuti, PhD, MSc, DDS, Systematic Review Efficacy of preprocedural mouthrinses in the reduction of microorganisms in aerosol, JADA 2019:150(12):1015-1026 https://www.researchgate.netpublication/337440953_Efficacy_of_preprocedural_mouthrinses_in_the_reduction_of_ microorganisms_in_aerosol_A_systematic_review
  9. R Izzetti, M Nisi, M Gabriele, F Graziani, COVID-19 Transmission in Dental Practice: Brief Review of Preventive Measures in Italy,Review J Dent Res. 2020 Aug;99(9):1030-1038
  10. Daniel L. Popkin, Sarah Zilka, Matthew Dimaano, Hisashi Fujioka, Cristina Rackley, RobertSalata, Alexis Griffith, Pranab K. Mukherjee, Mahmoud A. Ghannoum, Frank Esper, Cetylpyridinium Chloride (CPC) Exhibits Potent, Rapid Activity Against Influenza Viruses in vitro and in vivo, Pathogens and Immunity 2017;2(2):252-269