In vitro inactivation of SARS-CoV-2 using a povidone-iodine oral rinse

Abstract

Background Healthcare professionals, especially dentists and dental hygienists, are at increased risk for contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through air-borne particles and splatter. This study assessed the in vitro virucidal activity of 0.5% (w/v) povidone-iodine (PVP-I) oral rinse against SARS-CoV-2 to demonstrate its utility as a professional oral rinse. Methods A 0.5% (w/v) PVP-I oral rinse formulation, placebo oral rinse, and positive (70% [v/v] ethanol and water) and negative (water) controls were assessed using the time-kill method. SARS-CoV-2 was propagated in Vero 76 host cells. Following neutralization validation, triplicate tests were performed for each test formulation and virucidal activity measured at 15, 30, and 60 s and 5 min. Results The 0.5% (w/v) PVP-I oral rinse demonstrated effective in vitro virucidal activity against SARS-CoV-2 as early as 15 s after exposure; viral titer was reduced to < 0.67 log10 50% cell culture infectious dose (CCID50)/0.1 mL (log10 reduction of > 4.0) at 30 s, whereas the placebo oral rinse reduced the SARS-CoV-2 viral titer to 4.67 and 4.5 log10 CCID50/0.1 mL at the 15- and 30-s time points, with a log10 reduction of 0.63 and 0.17, respectively. No toxicity or cytotoxic effects against Vero 76 host cells were observed with the 0.5% (w/v) PVP-I oral rinse; positive and negative controls performed as expected. Conclusions In vitro virucidal activity of 0.5% (w/v) PVP-I oral rinse against SARS-CoV-2 was demonstrated. Rapid inactivation of SARS-CoV-2 was observed with 0.5% (w/v) formulation with a contact duration of 15 s. Clinical investigations are needed to assess the effectiveness of PVP-I oral rinse against SARS-CoV-2 in dental practice.

In vitro virucidal activity of mouthwashes on SARS‐CoV‐2

“…The commercial availability of pre‐procedural mouthwashes with specific antiviral properties against SARS‐CoV‐2 is regarded as a safe device for medical and dental practitioners. To date, CPC or iodine‐povidone (PVP‐I)‐based mouthwashes are the most recommended to reduce SARS‐CoV‐2 viral load in droplets and aerosols generated during dental procedures (Herrera et al, 2020 ; Seneviratne et al, 2021 ; Shet et al, 2022 ; Xu et al, 2021 ). However, the use of PVP‐I is contraindicated in patients with allergy to iodine, with thyroid disease, pregnancy, or treatment with radioactive iodine (Gray et al, 2013 ).…”

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

“…49,152 The latter is consistent with the in vitro action of this compound against the virus. 153,154 Sustained residual effects of povidone-iodine on skin in a model system have been suggested. 152 Environmental fogging with dilutions of hypochlorous acid has been assessed, and presumed inactivation is concentration and time dependent.…”

“… 49 , 152 The latter is consistent with the in vitro action of this compound against the virus. 153 , 154 Sustained residual effects of povidone–iodine on skin in a model system have been suggested. 152 …”

“…Concentrations of ethanol ranging from 40% to 80% show strong antiviral properties whether for surfaces or for skin. 49 , 72 , 75 , 77 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 Exposure in vitro to 70% ethanol results in rapid reduction of virus as early as 15–30 s. 154 Concentrations less than 30%, although having some effect, are limited for the rapidity of virucidal effects. 158 , 162 Isopropanol has generally been assessed at 70% vol/vol unless in combinations with ethanol.…”

“…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 , 175 , 176 , 177 , 178 , 179 , 180 , 181 , 182 , 183 , 184 , 185 , 186 Efficacy during in vitro or in vivo experiments has yielded variable results. Komine et al 175 did not find efficacy for chlorhexidine.…”