CPC-containing oral rinses inactivate SARS-CoV-2 variants and are active in the presence of human saliva

Abstract

Introduction. The importance of human saliva in aerosol-based transmission of SARS-CoV-2 is now widely recognized. However, little is known about the efficacy of virucidal mouthwash formulations against emergent SARS-CoV-2 variants of concern and in the presence of saliva. Hypothesis. Mouthwashes containing virucidal actives will have similar inactivation effects against multiple SARS-CoV-2 variants of concern and will retain efficacy in the presence of human saliva. Aim. To examine in vitro efficacy of mouthwash formulations to inactivate SARS-CoV-2 variants. Methodology. Inactivation of SARS-CoV-2 variants by mouthwash formulations in the presence or absence of human saliva was assayed using ASTM International Standard E1052-20 methodology. Results. Appropriately formulated mouthwashes containing 0.07 % cetylpyridinium chloride but not 0.2 % chlorhexidine completely inactivated SARS-CoV-2 (USA-WA1/2020, Alpha, Beta, Gamma, Delta) up to the limit of detection in suspension assays. Tests using USA-WA1/2020 indicates that efficacy is maintained in the presence of human saliva. Conclusions. Together these data suggest cetylpyridinium chloride-based mouthwashes are effective at inactivating SARS-CoV-2 variants. This indicates potential to reduce viral load in the oral cavity and mitigate transmission via salivary aerosols.

Antiviral effect of cetylpyridinium chloride in mouthwash on SARS-CoV-2

“…However, considering the complexity of the experimental technique and possibility of errors in the duration of action among samples, the minimum duration of action was set to 10 min in our study. In this regard, Anderson et al have clarified the effect of CPC at an action time of 30 s using a method to neutralize CPC 26 . Thus, it is warranted to develop new products, such as tablets, drops, and patches that can release CPC at a safe concentration and can be retained in oral cavity for as long as possible.…”

Disinfection and decontamination in the context of SARS‐CoV‐2‐specific data

“…Komine et al 175 did not find efficacy for chlorhexidine. Others found reduced efficacy for hydrogen peroxide and chlorhexidine 150,177,179,180 . Cetylpyridinium chloride in various dilutions inactivates virus, and the mechanism of action in part appears to be related to the interruption of the Spike protein/receptor complex 150,169,186 .…”

“…Both duration of administration and sampling site affect perceptions of efficacy. Formulations including hydrogen peroxide, benzalkonium chloride, dequalinium chloride, chlorhexidine, cetylpyridinium chloride, octenidine dihydrochloride, povidone–iodine, alkaline solutions, ethanol, hexetidine, cyclodextrin, polyaminopropyl biguanide, bioflavonoids, hypochlorous acid, delmopinol, silver nanoparticles, combination surfactants, essential oils, hydroxyapatite, glycyrrhizic acid, and/or sodium fluoride have been assessed 150,154,169,172,174–186 . Efficacy during in vitro or in vivo experiments has yielded variable results.…”

Mechanisms of Antimicrobial Agent Cetylpyridinium Chloride Mitochondrial Toxicity in Rodent and Primary Human Cells: Super-resolution Microscopy Reveals Nanostructural Disruption

“…For example, CPC in mouthwash (Muñoz-Basagoiti et al ., 2020) and in lozenge form (Steyer et al ., 2021) is effective against SARS-CoV2 (Alemany et al ., 2022): CPC lyses viral particles (Koch-Heier et al ., 2021; Bañó-Polo et al ., 2022) and inhibits viral fusion (Muñoz-Basagoiti et al ., 2020). Importantly, CPC’s virucidal potency is not dampened in the presence of human saliva nor by current viral variants (Muñoz-Basagoiti et al ., 2020; Anderson et al ., 2022).…”