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

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

Lozenges containing the antiseptics and local anesthetics amylmetacresol (AMC)/dichlorobenzyl alcohol (DCBA) or hexylresorcinol (HR) are commonly used to treat the symptoms of sore throat. In 2005, Oxford et al 5 published that lozenges containing AMC and DCBA showed some virucidal effect in vitro on three enveloped viruses, such as RSV, influenza A virus, and a member of the coronavirus family, SARS-CoV. However, they were not active against non-enveloped HRV2 and a not otherwise specified member of adenovirus group C. Recently, Shephard and Zybeshari 6 showed some virucidal effect of AMC/DCBA and HR either as free substances or processed into lozenges on PIV3 and Cytomegalovirus or on PIV3 only, respectively. The mechanism of the virucidal action is not clear. However, the authors suggest a denaturation of external protein spikes, a pH-induced rearrangement of the tertiary structure of attachment proteins, or some selective effect on viral lipid membranes/protein-lipid interaction to be responsible for the morphological changes and the virucidal action. 5, 6 An approved antiviral that interacts with the viral surface is iota-carrageenan, a high molecular weight sulfated polymer derived from the red seaweed. The antiviral activity of iota-carrageenan is well-established. We published that it is a potent inhibitor of HRV1a, 2, 8, 14, 16 , and 83 7 and influenza virus A replication in vitro and in vivo 8 and demonstrated the antiviral efficacy against common cold viruses by intranasal administration in several randomized, double-blind, parallel group, placebo-controlled clinical trials. [9] [10] [11] [12] In order to treat viral throat infections, we developed lozenges containing 10 mg iota-carrageenan/lozenge as an active ingredient. Ten milligrams were chosen to guarantee antiviral activity throughout the whole dissolution process in the mouth, where all the lozenges components are diluted due to saliva production.