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

Morokutti-Kurz, Martina; Graf, Christine; Prieschl-Grassauer, Eva

for lozenges containing AMC/DCBA at a low pH. Currently a series of such lozenges with the same active ingredients but different flavors is available; additionally, lozenges were marketed, containing HR, as active agent. Shephard and Zybeshari 6 tested the virucidal effect of AMC/DCBA and HR either as free substances or processed into lozenges. The experimental setup was the same in both publications. Lozenges were diluted in 5 or 4.5 mL artificial saliva or medium. Nine parts of the lozenges solution were then directly mixed with one part of the respective virus stock at a known titer. After different contact times, the residual infective virus was determined using quantitative titration. Oxford et al 5 also checked for morphological changes using electron microscopy and found clumping of viruses and denaturation of spike proteins within 2 minutes of contact time. From these results it is concluded that lozenges containing either AMC/DCBA or HR might exhibit a local antiviral effect in patients with sore throat due to viral RTIs. However, the experimental setup does not allow the extrapolation of these data to a potential clinical effect. Dissolution of the lozenge in the mouth stimulates saliva production, resulting in a flow rate of 1.5-6 mL saliva/minute. 14 As a consequence, 20-80 mL saliva were produced during the whole dissolution process of 13 minutes and 20 seconds. Therefore, the concentration of matrix and active ingredients at which the effect of the AMC/DCBA or HR containing lozenges was