Soothing relief from sores and ulcers. Iglu Sugar Free Pastilles dissolve slowly to soothe the pain and discomfort caused by mouth ulcers and sore gums. Simply let an Iglu Sugar Free Pastille dissolve in your mouth to provide soothing relief and release the active ingredients. The pastilles contain two active ingredients; benzalkonium chloride solution and a compound called benzoin tincture. Between them, these ingredients have antiseptic properties, to help prevent infection.