Sore throat treatments contain demulcents, antibacterials and local anaesthetics, and many products contain combinations of these. One sore throat lozenge contains flurbiprofen, a non-steroidal anti-inflammatory drug (NSAID). 

Demulcents
Sucking anything produces saliva, which lubricates and soothes inflamed tissues and washes infecting organisms off them. Any lozenge or pastille, regardless of ingredients, will do this. Non-medicated glycogelatin-based demulcent pastilles, such as glycerin, lemon and honey pastilles or boiled sweets, may be as effective as anything for soothing a sore throat. Because they contain no medicament they can be used as often as necessary to stop the throat feeling dry, thereby relieving discomfort. Some products contain ingredients with volatile constituents, such as eucalyptus oil and menthol, which produce a sensation of clearing blocked nasal and upper respiratory passages and can be useful in relieving other symptoms of colds. The main disadvantage of most demulcent throat lozenges and pastilles is their high sugar content.

Antibacterials
The antibacterial compounds used in sore-throat lozenges are unlikely to be effective against the rhinoviruses that are largely responsible. A sore throat caused or complicated by a secondary bacterial infection, such as tonsillitis, would normally be treated with a systemic antibiotic. Gargles have the same drawback as lozenges insofar as most have no proven antiviral activity. In addition, contact time with infected tissue is extremely short. The main action of gargles is the mechanical removal of microbes from the pharynx, but levels of contamination build up again very quickly.

Local anaesthetics
Benzocaine is the only local anaesthetic included in sore-throat lozenges; benzocaine and lidocaine are used in sore-throat sprays. A local anaesthetic may be helpful if swallowing is uncomfortable. Local anaesthetics can cause sensitisation in some individuals with prolonged use, so usage should be limited to five days.

Anti-inflammatories

Flurbiprofen is an NSAID available in a lozenge for the relief of sore throat; there is evidence that it is effective and well tolerated.1 Ibuprofen is also effective. Benzydamine, a locally-acting NSAID with local anaesthetic and analgesic properties, is available as a throat rinse.