The treatment of sore throat, considered to be essentially due to viral infection, does not require the use of antibiotics. The recommended treatment is therefore based on the use of topical anaesthetics and antiseptics. Throat lozenges play a leading role in topical treatment by allowing immediate, massive and persistent release of the active molecule at the site of infection. The objective of this study was to demonstrate the short-term and long-term in vitro antimicrobial efficacy of Drill^® lozenges in relation to the main pathogens responsible for upper respiratory tract infections.

The bactericidal and virucidal activity in relation to the main microorganisms responsible for upper respiratory tract infections, including the H1N1 influenza virus, was evaluated after short (5minutes) and long (3h) contact times, according to a methodology complying with European standards for the evaluation of chemical antiseptics and disinfectants. In parallel, the global antibacterial activity was determined on 30 strains representative of the resident flora by determination of maximum inhibitory dilutions (MID) and maximum bactericidal dilutions (MBD).

Drill^® lozenges presented an antibacterial activity inducing significant (>90%) destruction of the main upper respiratory tract pathogens after a 5-minute contact time at high concentration and after a 3-hour contact time after dilution. Drill^® lozenges also exerted an antiviral activity inducing 2 log (99%) destruction of the H1N1 virus after a 5-min contact time at high concentration, with maintenance of this activity after dilution (3h). A homogeneous antibacterial activity was observed on the resident flora.

These in vitro tests confirm the value of chlorhexidine lozenges in the treatment of upper respiratory tract infections such as sore throat.