TANNIC ACID+ZINC CHLORIDE+CETRIMIDE is a combination of three drugs, namely: Tannic acid (astringent), Zinc chloride (hemostatic agent and astringent), and Cetrimide (antiseptic). Tannic acid is an astringent and protein that helps to contract skin cells, thereby healing and relieving irritation due to mouth ulcers. Zinc chloride is a hemostatic agent with astringent properties that prevent bleeding and toughen the skin. Cetrimide is an antibacterial that works by preventing microbe growth (bacteria) that could infect broken skin in the mouth.