Amylmetacresol/2,4-dichlorobenzyl alcohol, hexylresorcinol, or carrageenan lozenges as active treatments for sore throat

Figures & data

Table 1 Test products and their identity code

Test item	Active ingredient	pH
Lozenge #1	10 mg iota-carrageenan	5.6
Lozenge #2	2.4 mg HR	5.2
Lozenge #3	1.2 mg DCBA/0.6 mg AMC	2.2
Lozenge #4	1.2 mg DCBA/0.6 mg AMC	5.8
Lozenge #5	1.2 mg DCBA/0.6 mg AMC	2.3
Lozenge #6	1.2 mg DCBA/0.6 mg AMC	3.7
Lozenge #7	1.2 mg DCBA/0.6 mg AMC	2.3
Lozenge #8	1.2 mg DCBA/0.6 mg AMC	2.3
Lozenge #9	1.2 mg DCBA/0.6 mg AMC	2.2

Notes: Lozenge #1 (Coldamaris^®) was manufactured by MoNo chem-pharm Produkte GmbH, Vienna, Austria. Lozenge #2 (Strepsils^® Max), lozenge #3 (Strepsils^® Original), lozenge #4 (Strepsils^® Extra Strong), lozenge #5 (Strepsils^® Warm), lozenge #6 (Strepsils^® Orange + Vitamin C), lozenge #7 (Strepsils^® Sugar free Lemon), lozenge #8 (Strepsils^® Children/Strawberry), and lozenge #9 (Strepsils^® Soothing Honey & Lemon) were manufactured by Reckitt Benckiser Healthcare Manufacturing (Thailand) Ltd., Bangplee, Samutprakarn, Thailand.

Abbreviations: AMC, amylmetacresol; DCBA, 2,4-dichlorobenzyl alcohol; HR, hexylresorcinol.

Figure 1 hCoV OC43 hemagglutination inhibition by Strepsils^® and Coldamaris^® lozenges solutions.

Notes: The dilution factor is indicated in the left column and the corresponding iota-carrageenan concentrations of the Coldamaris solutions in the top right column. The iota-carrageenan concentration of the assay reference is shown in the bottom right column. The agglutination control and all samples in the presence of virus (+) are tested in triplicates; agglutination control in the absence of the virus (−) as singlet. Fully agglutinated wells indicate the absence of antiviral activity of the lozenges solution at this specific dilution. Accordingly, the horizontal line shows the minimal inhibitory dilution/concentration at which the lozenges solution/iota-carrageenan reference still exhibits antiviral activity. Lozenge #1 (Coldamaris^®), lozenge #2 (Strepsils^® Max), lozenge #3 (Strepsils^® Original), lozenge #4 (Strepsils^® Extra Strong), lozenge #5 (Strepsils^® Warm), lozenge #6 (Strepsils^® Orange + Vitamin C), lozenge #7 (Strepsils^® Sugar free Lemon), lozenge #8 (Strepsils^® Children/Strawberry), and lozenge #9 (Strepsils^® Soothing Honey & Lemon).
Abbreviations: AMC, amylmetacresol; DCBA, 2,4-dichlorobenzyl alcohol; hCoV, human coronavirus; HR, hexylresorcinol.

Table 2 Antiviral activity against HRV1a and HRV8

Effectiveness against HRV1a	ID50 (dilution 1: ×) ±95% CI	Superiority of lozenge #1
Lozenge #1 (1)	1273.0±409.0	NA
Lozenge #2 (1)	150.4±55.4	8.5-fold
Lozenge #3 (1)	34.4±21.6	37.0-fold
Lozenge #1 (2)	496.0±131.0	NA
Lozenge #4 (2)	246.0±41.0	2.0-fold
Lozenge #5 (2)	75.4±42.1	6.6-fold
Effectiveness against HRV8
Lozenge #1 (1)	1115.0±671.0	NA
Lozenge #2 (1)	<50	>22.3-fold
Lozenge #3 (1)	<16	>69.7-fold
Lozenge #1 (2)	889.0±302.0	NA
Lozenge #4 (2)	<16	>55.6-fold
Lozenge #5 (2)	<16	>55.5-fold

Notes: ID₅₀ values of the lozenges solutions and lower and upper 95 % CI were calculated for a sigmoidal dose response model with XLfit Excel add-in version 5.3.1. Lozenges containing either AMC/DCBA (#3, #4, #5) or HR (#2) were tested in two separate setups (1) and (2), each in parallel with lozenge #1 (carrageenan) as anti-virally active reference. Lozenge #1 (Coldamaris^®), lozenge #2 (Strepsils^® Max), lozenge #3 (Strepsils^® Original), lozenge #4 (Strepsils^® Extra Strong), lozenge #5 (Strepsils^® Warm).

Abbreviations: ID₅₀, half maximal inhibitory dilution factor; CI, confidence intervals; AMC/DCBA amylmetacresol/2,4-dichlorobenzyl alcohol; HR, hexylresorcinol; NA, not applicable.

Table 3 Antiviral activity against Coxsackievirus A10

Effectiveness against Coxsackievirus A10	ID50 (dilution 1:×) ±95% CI	Superiority of lozenge #1
Lozenge #1	234.0±62.5	NA
Lozenge #2	<83.3	>2.8-fold
Lozenge #3	<8	>29.3-fold
Lozenge #4	<8	>29.3-fold
Lozenge #5	21.0±4.9	11.1-fold

Notes: ID₅₀ values of the lozenges solutions and lower and upper 95 % CI were calculated for a sigmoidal dose response model with XLfit Excel add-in version 5.3.1. Lozenges containing either HR (#2, [Strepsils^® Max]) or AMC/DCBA (#3 [Strepsils^® Original], #4 [Strepsils^® Extra Strong], #5 [Strepsils^® Warm]) were tested in parallel with lozenge #1 (Coldamaris^®, carrageenan) as anti-virally active reference.

Abbreviations: ID₅₀, half-maximal inhibitory dilution factor; CI, confidence intervals; AMC/DCBA amylmetacresol/2,4-dichlorobenzyl alcohol; HR, hexylresorcinol; NA, not applicable.

Table 4 Antiviral activity against influenza virus A H1N1n

Effectiveness against IV A H1N1n	ID50 (dilution 1:×) ±95% CI	Superiority of lozenge #1
Lozenge #1	4524±1045.0	NA
Lozenge #2	<20	>226.2-fold
Lozenge #3	9.7±2037.0	464.4-fold

Notes: ID₅₀ values of the lozenges solutions and lower and upper 95 % CI were calculated for a sigmoidal dose response model with XLfit Excel add-in version 5.3.1. Lozenges containing either HR (#2 [Strepsils^® Max]) or AMC/DCBA (#3 [Strepsils^® Original]) were tested in parallel with lozenge #1 (Coldamaris^®, carrageenan) as anti-virally active reference.

Abbreviations: CI, confidence interval; IV, influenza virus; ID₅₀, half maximal inhibitory dilution factor; NA, not applicable.

Figure 2 Time-dependent reduction of free influenza virus A H1N1n and hCoV OC43 by binding to iota-carrageenan beads.

Notes: Incubation times are indicated on the x-axis. The graph shows the amount of unbound virus in the supernatant (indicated on the y-axis) as percent of the virus concentration in the absence of iota-carrageenan beads (100% virus in supernatant), and the standard deviation of duplicates.
Abbreviation: hCoV, human coronavirus.