Difflam Spray contains the active substance benzydamine hydrochloride and belongs to a group of medicines called non-steroidal anti-inflammatory drugs or NSAIDS. Difflam Spray works by stopping pain and swelling (inflammation). It is used to treat many painful conditions of the mouth or throat including: Mouth ulcers Teething Sore throat Sore tongue or gums Discomfort associated with dentures or dental work.