The firm said it had already obtained promising results from preliminary lab studies, completed in October with Rutgers New Jersey Medical School. The laboratory research investigated the effects of toothpastes containing zinc or stannous and mouthwashes containing cetylpuridinium chloride (CPC) on the SARS-CoV-2 virus that caused COVID-19.
Early-stage findings – not audited or peer-reviewed – suggested its Total and Meridol toothpastes neutralised 99.9% of the virus after two minutes of contact and its Plax and Total mouthwashes had the same effect after 30 seconds. Colgate-Palmolive said current data suggested these oral care products neutralised the SARS-CoV-2 by targeting the viral envelop to dissolve it, something it would investigate further in its clinical studies.
Earlier this month, fellow personal care major Unilever also released details of its ongoing work in the same research space – lab and clinical – bearing very similar prelim results on CPC mouthwash.
‘Early stages of our clinical investigations’
Colgate-Palmolive said its lab work on toothpastes and mouthwashes formed part of a wider research programme that included clinical trials among people infected with COVID-19 to “assess the efficacy of oral care products in reducing the amount of the virus in the mouth”.
“We’re at the early stages of our clinical investigations, but our preliminary laboratory and clinical results are very promising,” said Dr Maria Ryan, chief clinical officer at Colgate-Palmolive.
Results from a clinical study that Colgate-Palmolive had sponsored, involving 50 hospitalised subjects, were set to be released next month. The company was also engaged in further early-stage clinical studies with American public research university Rutgers; the Albert Einstein Institute in Brazil; and the Chapel Hill Adams School of Dentistry at the University of North Carolina that collectively involved around 260 COVID-infected persons.
“Colgate is collaborating with numerous investigators throughout the globe to conduct clinical research to explore the potential of oral care products to reduce oral viral loads as a risk reduction strategy,” Ryan said.
Understanding SARS-CoV-2 transmission
Dr Mark Wolff, Morton Amsterdam Dean of Penn dental medicine at the University of Pennsylvania, said: “With this pandemic, the more we understand about the virus, the more effective we can be in fighting it, so I am excited to see the impressive research program Colgate has undertaken.”
Wolff said these clinical studies may be able to demonstrate “additional ways to address the transmission of disease among people in close contact, particularly in dental practice”.
Colgate-Palmolive acknowledged, however, that there was currently “no conclusive evidence” that reducing virus levels in the mouth prevented getting or transmitting the virus.
Despite this, Dr David Alland, lead researcher of the Colgate-Rutgers study and director of the Center for COVID-19 Response and Pandemic Preparedness at the institute, said because saliva contained comparable amounts of the virus to levels found in the nose and throat, it seemed “likely that SARS-CoV-2 virus originating in the mouth contributes to disease transmission, especially in persons with asymptomatic COVID-19, who are not coughing”.
“This suggests that reducing virus in the mouth could help prevent transmission during the time that oral care products are active,” Alland said.
Further study necessary around anti-viral effects
The length of time these oral care products remained active, however, was a critically important aspect in advancing studies and understanding around virus transmission, according to Professor Iain Chapple, head of research for the Institute of Clinical Sciences at the UK’s University of Birmingham. Speaking at the time Unilever unveiled its preliminary results on CPC mouthwash, Chapple said in-vitro and human clinical studies had to form part of “further exploration” to understand how long any anti-viral effects lasted.