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. 2023 Oct 11;59:334–356. doi: 10.1016/j.jdsr.2023.09.003

Table 5.

Main features of in vitro studies.

Ref. Test (type, concentration, exposure time) Control SARS-CoV2 source Assessment method Initial viral concentration Incubation temperature Reduction in viral titer compared to non-active control Main results
Almanza-Reyes et al., 2021[114] AgNPs at concentrations of 0.5–0.0004% (24 h; 48 h; 72 h) Virus + culture medium SARS-CoV-2 NL/2020 strain (BetaCoV/Netherlands/01) Plaque assay Serial two-fold dilutions from 1/2–1/2048 37 °C Percentages of infectivity: 0.03% AgNPs reduces infectivity by 80% Although AgNPs did not totally abolish viral production, infection was clearly controlled to some extent with a viral load reduction of about 80% at a concentration of 0.03%. A 50% inhibitory concentration was determined by curve fitting (non-linear regression).
Anderson et al., 2022[126]
  • 1.

    MW-A: CPC 0.07% + herbal extracts (30 s)

  • 2.

    MW-B: CPC 0.07% with flavour (with and without saliva) (30 s)

  • 3.

    MW-C: CHX digluconate 0.2% + ethanol 7% (30 s)
  • 1.

    EtOH 70% (30 s)

  • 2.

    Distilled water (30 s)

 SARS-CoV-2 variants:
  • 1.

    USA-WA1/2020

  • 2.

    alpha: hCoV-19/England/204820464/2020

  • 3.

    beta: hCoV-19/South Africa/KRISP- EC-K005321/2020

  • 4.

    delta: SARS-CoV-2/human/GBR/Liv_273/2021, GenBank accession OK392641

  • 5.

    gamma: hCoV-19/Japan/TY7–503/2021

 Plaque assay 1/10 dilution starting from unknown concentration 37 °C Log10PFU/mL reduction
  • 1.

    variant alpha: MW-A, MW-B and EtOH: 3.11

  • 2.

    variant beta: MW-A, MW-B, EtOH: 4.11

  • 3.

    variant gamma: MW-A, MW-B, EtOH: 3.36

  • 4.

    variant delta: MW-A, MW-B, EtOH: 4.52

 Mouthwashes containing CPC 0.07% effectively inactivated SARS-CoV-2 with greater than 4.0 Log10 PFU/mL reduction in viral titre. Virucidal activity of CPC was maintained in presence of human saliva. Both CPC 0.07% mouthwashes were as effective as ethanol 70% against four variants. The mouthwash containing CHX digluconate 0.2% did not have substantial action against SARS-CoV-2 in vitro.
Bidra et al., 2020[109]
  • 1.

    H2O2 3% (15 s; 30 s)

  • 2.

    H2O2 1.5% (15 s; 30 s)

  • 3.

    PVP-I 1.5% (15 s; 30 s)

  • 4.

    PVP-I 1.25% (15 s; 30 s)

  • 5.

    PVP-I 0.5% (15 s; 30 s)
  • 1.

    EtOH 70% (15 s; 30 s)

  • 2.

    Water (15 s; 30 s)

 SARS-CoV-2, USA-WA1/2020 Plaque assay 5.0 Log10 CCID50/0.1 mL 22 ± 2 °C Log10CCID50/0.1 mL
  • 1.

    H2O2 3%: 15 s: ≤ 4.0%; 30 s: ≤ 2.5%

  • 2.

    H2O2 1.5%: 15 s: ≤ 3.67%; 30 s: ≤ 3.33%

  • 3.

    PVP-I: at all concentrations and timepoint < 0.67

  • 4.

    EtOH: both after 15 s and 30 s < 0.67

  • 5.

    Water: 15 s: 5.0; 30 s: 4.3

 After 15 s all the three concentrations of PVP-I were equally effective in reducing the SARS-CoV-2 load compared to the water control·H2O2 both at 3% and 1.5% concentration showed minimal viricidal effect after 15 and 30 s. Ethanol inactivated the virus similarly to the PVP-I products.
Bidra et al., 2020[108]
  • 1.

    PVP-I 1.5% (15 s; 30 s)

  • 2.

    PVP-I 0.75% (15 s; 30 s)

  • 3.

    PVP-I 0.5% (15 s; 30 s)
  • 1.

    EtOH 70% (15 s; 30 s)

  • 2.

    Water (15 s; 30 s)

 (SARS-CoV-2) USA-WA1/2020 Plaque assay 5.0 Log10 CCID50/0.1 mL 22 ± 2 °C Log10CCID50/0.1 mL
  • 1.

    PVP-I: at all concentrations and timepoint < 0.67

  • 2.

    EtOH: 15 s: 1.5; 30 s: < 0.67

  • 3.

    Water: 15 s: 3.67; 30 s: 4.0

 After 15 s all the three concentrations of PVP-I were equally effective in reducing the SARS-CoV-2 load compared to the water control. EtOH 70% was unable to completely inactivate SARS-CoV-2 after 15 s but was able to inactivate the virus after 30 s. No cytotoxicity was observed with any of the test compounds.
Chen et al., 2022[117] Hexadecyl pyridinium chloride (0.2, 0.1, 0.05, 0.025, or 0.0125 mg/mL) (30 s; 60 s; 120 s; 300 s) Culture medium + test solution SARS-CoV-2 (hCoV-19/Zhejiang/OS2/2020, GISAID, ID: 455692) isolated from a patient at the Zhejiang Provincial Center for Disease Control and Prevention
  • 1.

    Plaque assay

  • 2.

    RT-PCR

  • 3.

    Immunofluorescence

 3 × 103 U/mL 35 °C Log TCID50/mL reduction
  • 1.

    0.025 and 0.0125: > 10 for each contact time

  • 2.

    0.05: < 10 only after 300 s

  • 3.

    0.2 and 0.1: ∼ 5 for each contact time

 The disinfection effect of hexadecyl pyridinium chloride is time and concentration-dependent, with the strongest virus-elimination effect at a concentration of 0.1 mg/mL for 2 min
da Silva Santos et al., 2021[115] APD 2.0 mg/mL (30 min) Virus + culture medium SARS.CoV2/SP02.2020. HIAE. Br
  • 1.

    RT-PCR

  • 2.

    Fluorescent assay

 1 × 102 TCID50/mL 37 °C RT-PCR reduction in viral load at:
  • 1.

    1:2 titers: 99.96%

  • 2.

    1:4 titers: 99.88%

  • 3.

    1:8 titers: 99.84%

  • 4.

    1:16 titers: 92.65%

  • 5.

    1:32 titers: 77.42%

  • 6.

    1:64 titers: 11.06%

 APD, when compared to the control, showed a significant reduction in SARS-CoV-2 load at 1:2, 1:4, 1:8 and 1:16 dilution, and partially inactivated SARS-CoV-2 at 1:32 and 1:64 dilution. Cytotoxic effect was detected only at the initial dilution 2 mg/mL (2:1). No virus neutralization was observed below the 1:128 titer.
Davies et al., 2021[105]
  • 1.

    CHX 0.2% + EtOH (60 s)

  • 2.

    CHX 0.2% alcohol-free (60 s)

  • 3.

    Dipotassium oxalate 1.4% (60 s)

  • 4.

    Hypochlorous acid 0.01–0.02% (60 s)

  • 5.

    H2O2 1.5% (60 s)

  • 6.

    PVP-I 0.58% (60 s)

 Medium + test solution (60 s) SARS-CoV-2 England 2 strain Plaque assay 1.7 × 106 TCID50/mL 20 ± 2 °C Mean titre reduction (Log10TCID50/mL)
  • 1.

    CHX + EtOH: 0.5 (0.1–0.9)

  • 2.

    CHX alcohol free: 0.2 (−0.2 to 0.7)

  • 3.

    Dipotassium oxalate: ≥ 3.5 (3.2–3.8)

  • 4.

    Hypochlorous acid: ≥ 5.5 (5.2–5.8)

  • 5.

    H2O2: 0.2 (−0.1 to 0.5)

  • 6.

    PVP-I: ≥ 4.1 (3.8–4.4)

 Dipotassium oxalate demonstrated effective inactivation of SARS-CoV-2 in vitro and by commercial mouthwashes containing 0.01–0.02% hypochlorous acid or 0.58% PVP-I, while both the CHX and H2O2 mouthwashes tested in this study resulted to be ineffective against SARS-CoV-2.
Jain et al., 2021[99]
  • 1.

    CHX 0.2% (30 s; 60 s)

  • 2.

    CHX 0.12% (30 s; 60 s)

  • 3.

    PVP-I 1% (30 s; 60 s)

 _ SARS-CoV-2 strain isolated from an Indian patient and cultured using VeroE6 cells RT-PCR 2 × 106 PFU/mL 37 °C Relative Ct change
  • 1.

    CHX 0.12%: 30 s: 10.5 ± 0.5; 60 s: 11 ± 1.0

  • 2.

    CHX 0.2%: 30 s: 12.5 ± 0.5; 60 s: 13 ± 0

  • 3.

    PVP-I: 30 s: 9.5 ± 0.5; 60 s: 11 ± 2

 CHX 0.2% inactivated more than 99.9% of SARS-CoV-2 virus after a contact time of 30 s, and was considered as more efficacious than PVP-I 1% utilized for 30 s and 60 s
Koch-Heier et al., 2021[100]
  • 1.

    CPC 0.05% + H2O2 1.5% (30 s)

  • 2.

    CHX 0.1% + CPC 0.05% + F- 0.005% (30 s)

  • 3.

    CPC 0.05% (30 s)

  • 4.

    CHX 0.1% (30 s)

  • 5.

    CPC 0.05% + CHX 0.1% (30 s)

  • 6.

    H2O2 1.5% (30 s)
  • 1.

    SARS-CoV-2 + medium

  • 2.

    Medium + each test solution

 SARS-CoV-2 strain FI-100 Plaque assay 6.25 × 106 PFU/mL 37 °C Log10PFU/mL reduction
  • 1.

    CPC + H2O2: ≥ 1.9

  • 2.

    CHX+CPC+F-: ≥ 2.0

  • 3.

    CPC: 0.7

  • 4.

    CHX: 0.55

  • 5.

    CPC+CHX: 1.2

  • 6.

    H2O2: 0.3

 While a combination of CPC and CHX as well as CPC alone led to a significant reduction of infectious viral particles, H2O2 and CHX alone had no virucidal effect against SARS-CoV-2. At the crystal violet staining A reduction resulted from 0.05% CPC and the combination of 0.1% CHX with 0.05% CPC, while no virucidal effect was observed for 0.1% CHX and 1.5% H2O2.
Komine et al., 2021[101]
  • 1.

    CPC 0.05% (20 s)

  • 2.

    CHX 0.06% + CPC 0.05% (30 s)

  • 3.

    CHX 0.12% + CPC 0.05% (30 s)

  • 4.

    CPC 0.075% (30 s)

  • 5.

    CHX 0.12% (30 s)

  • 6.

    Delmopinol hydrochloride 0.20% (30 s)

  • 7.

    CPC 0.04% (20 s)
  • 1.

    EtOH 70% (20 s)

  • 2.

    Water (20 s, 30 s, 180 s)

 SARS-CoV-2 (JPN/TY/WK-521 strain) Plaque assay 0.1 mL of virus suspension (viral titer 8.49 Log10 PFU/mL) 25 °C
  • 1.

    EtOH: > 99.99%

  • 2.

    CPC (0.05%; 0.075%; 0.04%): ≥ 99.99%

  • 3.

    CHX (0.06% or 0.12%) + CPC: > 99.99%

  • 4.

    CHX: 42.5%

  • 5.

    Delmopinol hydrochloride: > 99.99%

 No cytotoxic or interference effects at dilutions ranging from 1 to 1/100 for any of the tested solutions.
All the mouthwashes containing 0.4–0.075% CPC inactivated SARS-CoV-2 with a reduction of 3.3 to > 4.4 Log10 PFU/mL regardless of dosage. Mouthwash containing 0.20% delmopinol hydrochloride inactivated SARS-CoV-2 with a > 5.4 Log10 PFU/mL reduction. However, the mouthwash containing only 0.12% CHX as antiseptic did not show a sufficient inactivation effect against SARS-CoV-2 in this study.
Meister et al., 2020[104]
  • 1.

    H2O2 1.5% (30 s)

  • 2.

    CHX 0.2% (A) (30 s)

  • 3.

    Dequonal® (0.015% Dequalinium chloride; 0.035% Benzalkonium chloride) (30 s)

  • 4.

    CHX 0.2% (B) (30 s)

  • 5.

    PVP-I 1% (30 s)

  • 6.

    Listerine® Cool Mint (Eucalyptol 0.091%; Menthol 0.042%; Thymol 0.063%, ethanol (inactive ingredient)) (30 s)

 SARS-CoV-2 + medium
  • 1.

    Strain 1: SARS-CoV-2 isolated from a patient

  • 2.

    Strain 2: BetaCoV/Germany/Ulm/01/2020

  • 3.

    Strain 3: BetaCoV/Germany/Ulm/02/2020

 Plaque assay 5 × 105 TCID50/mL in 1 vol of organic load mimicking respiratory secretions 37 °C TCID50/mL reduction
  • 1.

    H2O2: strain 1: 0.78; strain 2: 0.61; strain 3: 0.33

  • 2.

    CHX (A): strain 1: 1.00; strain 2: 0.78; strain 3: 1.17

  • 3.

    Dequonal®: strain 1: ≥ 3.11; strain 2: ≥ 2.78; strain 3: ≥ 2.61

  • 4.

    CHX (B): strain 1: 0.50; strain 2: 0.56; strain 3: 0.50

  • 5.

    PVP-I: strain 1: ≥ 3.11; strain 2: ≥ 2.78; strain 3: ≥ 2.61

  • 6.

    Listerine® Cool Mint: strain 1: ≥ 3.11; strain 2: ≥ 2.78; strain 3: ≥ 2.61

 Medium control after 30 s exposure time did not reduce viral infectivity. All the three SARS-CoV-2 strains were highly susceptible to various oral rinses. All tested products showed virucidal activity against SARS-CoV-2. In particular, Dequonal®, PVP-I and Listerine® Cool Mint, significantly reduced viral infectivity to up to 3 orders of magnitude to background levels. Evidence that SARS-CoV-2 can be efficiently inactivated by commercially available oral rinses within 30 s was provided.
Okamoto et al., 2022[112]
  • 1.

    CPC 0.05% (20 s; 60 s; 300 s)

  • 2.

    CPC 0.1% (20 s; 60 s; 300 s)

  • 3.

    CPC 0.3% (20 s; 60 s; 300 s)

  • 4.

    PVP-I 0.1% (20 s; 60 s; 300 s)

 SARS-CoV-2 + medium SARS-CoV-2/Hu/DP/Kng/19–027,LC528233: SARS-CoV-2 isolated from a patient who developed COVID-19 on the cruise ship Diamond Princess Plaque assay 10-fold dilution starting from unknown viral stock concentration Not reported % reduction
  • 1.

    CPC 0.05%: 91.9% at 20 s; > 97% at 60 s and 300 s

  • 2.

    CPC 0.1%: > 97% at all timepoints

  • 3.

    CPC 0.3%: > 97% at all timepoints

  • 4.

    PVP-I: > 97% at all timepoints

 CPC has dose- and time-dependent antiviral activity. In Western blotting after SDS-PAGE under reducing conditions, the molecular weights of four forms of the S protein were unchanged.
Pelletier et al., 2021[107]
  • 1.

    PVP-I 1.5% (60 s)

  • 2.

    PVP-I 0.75% (60 s)

  • 3.

    PVP-I 0.5% (60 s)
  • 1.

    EtOH 70% (60 s)

  • 2.

    Water (60 s)

 SARS-CoV-2, USA-WA1/2020 strain Plaque assay 5.3 Log10 CCID50/0.1 mL 22 ± 2 °C Log10CCID50/0.1 mL reduction
  • 1.

    PVP-I 1.5%: 4.63

  • 2.

    PVP-I 0.75%: 4.63

  • 3.

    PVP-I 0.5%: 4.63

  • 4.

    EtOH 70%: 4.63

 All the oral antiseptics evaluated were effective at reducing > 4 Log10 CCID50 infectious virus, from 5.3 Log10 CCID50/0.1 mL to 1 Log10 CCID50/0.1 mL or less. No cytotoxicity, or cell death, was observed in any of the test wells. Positive control and neutralization controls performed as expected and did not cause cell death.
Ramji et al., 2022[113]
  • 1.

    H2O2 1.5% (30 s)

  • 2.

    CPC 0.07% (30 s)

 Medium alone SARS-CoV-2 USA-WA1/2020 (NR-52281, BEI Resources; Manassas, VA, USA) Plaque assay 1:100 dilution for the mouth rinse; 1:10 dilution for the dentifrice 20 ± 2 °C
  • 1.

    Log10 TCID50/mL reduction

  • 2.

    H2O2: ≥ 4.22

  • 3.

    CPC: ≥ 4.22

 Both tested mouthwashes demonstrated strong virucidal activity in the virucidal efficacy suspension test after a 30 s contact time.
Santos et al., 2021[115] APD 0.1% (30 s, 60 s, 300 s)
  • 1.

    SARS-CoV-2 + medium

  • 2.

    Medium alone

 SARS-CoV-2 samples retrieved from oropharynx of patients diagnosed with the new COVID Plaque assay 5.5 ln TCDI50/mL 37 °C SARS-CoV-2 inactivation (%)
  • 1.

    ADP 30 s: 90%

  • 2.

    ADP 60 s: 90%

  • 3.

    ADP 300 s: 90%

 Mouthwash 0.1% APD presents 1 reduction Log10, with 90% viral inactivation, with the same percentage of reduction for all the exposure times performed.
Shet et al., 2022[111] PVP-I 0.5% (15 s; 30 s; 60 s; 300 s)
  • 1.

    Placebo (15 s; 30 s; 60 s; 300 s)

  • 2.

    EtOH 70% (15 s; 30 s; 60 s; 300 s)

  • 3.

    Water (15 s; 30 s; 60 s; 300 s)

 SARS-CoV-2, strain USA-WA1/2020 Plaque assay 1:2 dilution from the highest viral suspension 22 ± 2 °C Log10CCID50/0.1 mL reduction
  • 1.

    15 s: PVP-I 2.8; placebo: 0.63; ethanol 4.0

  • 2.

    30 s: PVP-I > 4.0; placebo: 0.17; ethanol: > 4.0

  • 3.

    60 s: PVP-I: 3.67; placebo: 0; ethanol: > 4.0

  • 4.

    300 s: PVP-I: > 4.0; placebo: 0; ethanol: > 4.0

 PVP-I 0.5% demonstrated effective virucidal activity against SARS-CoV-2 at all the timepoints, with a reduction of viral titer up to 2.5 and < 0.67 log10 CCID50/0.1 mL at 15 s and 30 s, respectively.
Steinhauer et al., 2021[103]
  • 1.

    CHX 0.08% (300 s; 600 s)

  • 2.

    CHX 0.16% (60 s; 300 s)

  • 3.

    OCT 0.08% (15 s; 30 s; 60 s)

  • 4.

    OCT 0.02% (15 s; 30 s; 60 s)

 SARS-CoV-2 + medium _ Plaque assay 0.7 × 106 PFU/mL _ TCID50/mL reduction
  • 1.

    CHX 0.08%: 300 s: 0.37; 600 s: 0.76

  • 2.

    CHX 0.16%: 60 s: 0.4; 300 s: 0.81

  • 3.

    OCT 0.08%: ≥ 2.02 at 15 s, 30 s, 60 s

  • 4.

    OCT 0.02%: ≥ 3.02 at 15 s, 30 s, 60 s

 The two formulations based on CHX were found to have only limited efficacy against SARS-CoV-2, while OCT demonstrated virucidal efficacy against SARS-CoV-2, meeting the > 4 Log10 requirement of EN 14476 within a contact time of only 15 s
Takeda et al., 2022[116] SP_T medical gargle (Commercial name)
  • 1.

    Plaque assay: CPC 0–50 μg/mL (30 min)

  • 2.

    Plaque assay with saliva: CPC 0–40 μg/mL (30 min)

  • 3.

    qRT-PCR: CPC 0–25 μg/mL (30 min)

  • 4.

    Western blotting: CPC 50 μg/mL (10 min)

  • 5.

    TEM: CPC 10, 50, 250 μg/mL (10 min)
  • 1.

    Surfactant Triton X-100

  • 2.

    PBS

 SARS-CoV-2 variants:
  • 1.

    Wuhan (WK-521;EPI_ISL_408667)

  • 2.

    alpha (QK002;EPI_ISL_768526)

  • 3.

    beta (TY8–612;EPI_ISL_1123289)

  • 4.

    gamma (TY7–501;EPI_ISL_833366)
  • 1.

    Plaque assay

  • 2.

    qRT-PCR

  • 3.

    Western blotting

  • 4.

    TEM

 107 PFU/mL, 1:2 dilution Room temperature SARS-CoV-2 inactivation
  • 1.

    CPC effects depend on viral strain: SARS-CoV-2 Gamma is the most sensitive; SARS-CoV-2 Wuhan is the most resistant.

  • 2.

    CPC effects are dose depend: 40 μg/mL reduced by 1 log SARS-CoV-2 Wuhan

  • 3.

    CPC effects are reduced in presence of saliva

 Plaque assay: CPC significantly suppressed the infectivity of all examined SARS-CoV-2 directly in a dose-dependent manner. CPC (50 μg/mL) treatment completely inactivated SARS-CoV-2 Wuhan strain similarly as Triton X-100 (1%). With saliva: CPC (25–40 μg/mL) significantly inactivate SARS-CoV-2 in saliva, in a dose-dependent manner.
qRT-PCR: Viral RNA expression level in the cells was significantly reduced by CPC via dose-dependent manner at 24 h postinfection.
Western blotting: PBS and CPC might have no effect on the structure of the SARS-CoV-2 virions, whereas Triton X-100 changed the structure.
TEM analysis: spherical particle structure of SARS-CoV-2 treated with PBS remained unchanged. Most virus particles treated with 10 μg/mL CPC remained unchanged, whereas some disintegrated with 50 μg/mL CPC. In contrast, almost all virus particles treated with 250 μg/mL CPC were clearly disrupted (like 1% Triton X-100).
Tiong et al., 2021[102]
  • 1.

    CHX 0.12% (30 s, 60 s)

  • 2.

    CPC 0.075% + F- 0.05% (30 s, 60 s)

  • 3.

    Thymol 0.05% (30 s, 60 s)

  • 4.

    Bactidol® (Hexetidine 0.1% + Ethanol 9%) (30 s, 60 s)
  • 1.

    Salt water (water + sodium chloride 2%)

  • 2.

    SARS-CoV-2 + medium

 SARS-CoV-2 virus isolated from NP/OP swab from a SARS-CoV-2-positive patient Plaque assay 5 × 104 TCID50/mL 37 °C Log10TCID50/mL reduction
  • 1.

    CHX: 4.00 for all the timepoints both in clean and dirty conditions

  • 2.

    CPC+F-: 5.00 for all the timepoints both in clean and dirty conditions

  • 3.

    Thymol: 0.5 at 30 s under clean conditions and at 30 s and 60 s under dirty conditions; 0.75 at 60 s under clean conditions

  • 4.

    Bactidol®: 5.00 for all the timepoints both in clean and dirty conditions

  • 5.

    Salt water: 0.00 for all the timepoints both in clean and dirty conditions

 In this study, Bactidrol® and CPC + F- mouthwashes were the most effective against SARS-CoV-2, decreasing more than the 99.99% of SARS-CoV-2 load compared to the control after 30 and 60 s of exposure, under both clean and dirty conditions. The virucidal activity of the CHX containing mouthwash against SARS-CoV-2 was slightly lower than the virucidal activity of Bactidrol® and CPC based mouthwashes, with a viral inactivation percentage of 99.99% under both clean and dirty conditions. Salt water and thymol did not show any significant reduction in viral load.
Wang et al., 2021[110]
  • 1.

    PVP-I 2 mg/mL (30 s, 60 s, 120 s or 300 s)

  • 2.

    PVP-I 1 mg/mL (30 s, 60 s, 120 s or 300 s)

  • 3.

    PVP-I 0.5 mg/mL (30 s, 60 s, 120 s or 300 s)

  • 4.

    PVP-I 0.25 mg/mL (30 s, 60 s, 120 s or 300 s)

  • 5.

    PVP-I 0.125 mg/mL (30 s, 60 s, 120 s or 300 s)

  • 6.

    PVP-I 0.0625 mg/mL (30 s, 60 s, 120 s or 300 s)

 Medium alone SARS-CoV-2 (hCoV-19/Zhejiang/OS2/ 2020, GISAID, ID: 455692) isolated from a patient in Zhejiang Provincial Centre for Disease Control and Prevention
  • 1.

    Plaque assay

  • 2.

    RT-PCR

  • 3.

    Immunofluorescence microscopy

 1 × 106 IU/mL, diluted 1:1000 35 °C Log10TCID50/mL
Medium ∼ 6 at all timepoints
  • 1.

    30 s: 2 < PVP-I 0.5, 1 and 2 mg/mL < 3; 5 < PVP-I 0.125 and 0.25 mg/mL < 6

  • 2.

    60 s: PVP-I 2 mg/mL < 2; PVP-I 1 mg/mL ∼ 2; PVP-I 0.5 mg/mL ∼ 3; PVP-I 0.125 and 0.25 mg/mL ∼ 6

  • 3.

    120 s: PVP-I 2 mg/mL < 2; PVP-I 1 and 0.5 mg/mL ∼ 2; PVP-I 0.25 mg/mL ∼ 5; PVP-I 0.125 mg/mL ∼ 6

  • 4.

    300 s: PVP-I 1 and 2 mg/mL < 2;PVP-I 0.5 mg/mL ∼ 3; PVP-I 0.25 and 0.125 mg/mL ∼ 6.

 Viral inhibitory effect at the same concentration was highest when the contact time was 1 min
RT-PCR: PVP-I at a concentration of 1000 μg/mL had no viral inhibition (CC50 > 2.75 mM). Effect of PVP-I on virus inhibition rate was mainly concentration dependent. The viral titres for the same contact time but different PVP-I concentrations decreased as the concentration of PVP-I increased. At high concentrations, prolonging the contact time does not enhance PVP-I virus suppression capability.
Xu et al., 2021[106]
  • 1.

    Listerine® Original (Eucalyptol 0.092%; Menthol 0.042%; Methyl salicylate 0.060%; Thymol 0.064%; Ethanol 26.9%; 30 min)

  • 2.

    PVP-I 1% (30 min)

  • 3.

    H2O2 1.5% (30 min)

  • 4.

    CHX 0.12% (30 min)

 SARS-CoV-2 + medium Pseudotype SARS-CoV-2 (USA_WA1/2020 strain) expressing mNeonGreen Fluorescent assay MOI 1:5 37 °C
  • 1.

    Listerine® original (3%v/v): reduced SARS-COV-2 infection by 40%

  • 2.

    PVP-I (0.1% v/v): high antiviral activity, but disruption of cell morphology was detectable

  • 3.

    H2O2 (0.05% v/v): high antiviral activity, but disruption of cell morphology was detectable

  • 4.

    CHX (1.5% v/v): reduced infection by 70% without affecting cells morphology

 All undiluted mouthwashes and both 1.5% (v/v) dilutions of HP and PVP-I were highly toxic to HeLa-hACE2 hACE2 and oral epithelial cells. All mouth washes at non-cytotoxic levels exhibited antiviral activity. Highly diluted PVP-I and H2O2 significantly inactivated viruses but their antiviral effects were associated with severe cytotoxicity at higher concentrations. Taken together, Listerine® Original and CHX may be better mouth rinse products for SARS-CoV-2 prevention since they did not show cytotoxic effects.

AgNPs: silver nanoparticles; APD: anionic phthalocyanine derivate; CCID50: 50% cell culture infectious dose; CHX: chlorhexidine; CPC: cetylpyridinium chloride; EtOH: ethanol; F-: sodium fluoride; H2O2: hydrogen peroxide; NP: nasopharyngeal; OCT: Octenidine dihydrochloride; OP: oropharyngeal; PBS: phosphate buffered solution; PVP-I: povidone-iodine; PFU: plaque-forming unit; TCID50: 50% tissue culture infectious dose; TEM: transmission electron microscopy.