Table 1.

Test substances and controls.

Test substance	Contact time
AMC/DCBA lozenge	1, 5 and 10 min
Strepsils® Honey and Lemon lozenge, containing 0.6 mg AMC and 1.2 mg DCBA, dissolved in 4.5 mL of artificial saliva⁎
Lozenge ingredients: AMC, DCBA, peppermint oil, terpeneless lemon oil, honey, tartaric acid, liquid glucose, liquid sugar, quinoline yellow
Placebo lozenge for AMC/DCBA experiments	1 and 10 min
Placebo lozenge, dissolved in 4.5 mL artificial saliva⁎
Lozenge ingredients: peppermint oil, terpeneless lemon oil, honey, tartaric acid, liquid glucose, liquid sugar, quinoline yellow
AMC/DCBA as free active substances	1 and 10 min
0.6 mg AMC and 1.2 mg DCBA dissolved in 4.5 mL artificial saliva⁎
Hexylresorcinol lozenge	1, 5 and 10 min
Strepsils Extra Cherry lozenge, containing 2.4 mg hexylresorcinol and 4 mg menthol, dissolved in 4.5 mL of artificial saliva⁎
Lozenge ingredients: hexylresorcinol, carmoisine edicol (dye), cherry flavour, menthol, liquid glucose, liquid sugar
Placebo lozenge for hexylresorcinol experiments	1 and 10 min
Placebo lozenge, dissolved in 4.5 mL artificial saliva⁎
Lozenge ingredients: carmoisine edicol (dye), cherry flavour, menthol, liquid glucose, liquid sugar
Hexylresorcinol as a free active substance	1 and 10 min
2.4 mg hexylresorcinol as a free active substance, dissolved in 4.5 mL artificial saliva⁎
Positive control	1 min
Sodium hypochlorite, 1000 ppm (1500 ppm for the hexylresorcinol experiments)
Negative control	10 min
Dilution medium (MEM + 3 μg/mL trypsin for the PIV3 experiments and MEM + 5% fetal bovine serum for the CMV experiments)

AMC, amylmetacresol; CMV, cytomegalovirus; DCBA, 2,4-dichlorobenzyl alcohol; MEM, minimum essential medium; PIV3, parainfluenza virus type 3.

^⁎4.2 g sodium bicarbonate, 0.5 g sodium chloride, and 0.2 g potassium carbonate was added to ∼900 mL of sterile deionized water. 3 g of bovine serum albumin was added to the solution and the pH adjusted to 6.5 ± 0.5. Sterile deionized water was added to reach a total volume of 1000 mL.