Trisodium phosphate in toothpaste is always used as buffer agent. Buffer agent refers to the chemical composition used to stabilize the PH value of toothpaste paste to avoid water and swelling caused by the dissociation of abrasives.
Toothpaste is a suspension colloidal system composed of solid and liquid phases. Each component has a specific pH. The stability of each component requires a specific pH environment. The use of buffers must ensure that the pH of the toothpaste is always controlled. The friction agent is within the stable PH range.
Phosphate is the most widely used toothpaste buffer. Calcium carbonate type toothpaste generally uses sodium pyrophosphate and calcium hydrogen phosphate as a buffer. Calcium hydrogen phosphate type toothpaste generally uses sodium pyrophosphate as a buffer. Aluminum hydroxide type toothpaste generally uses trisodium phosphate(tsp), sodium dihydrogen phosphate and disodium hydrogen phosphate as buffers.