Sodium saccharin, scientific name sodium phthalylsulfonimide, chemical formula is C7H4NO3SNa, white crystalline powder. The sweetness is 200 to 500 times that of sucrose, generally 300 times, and the sweetness threshold is about 0.00048%. It is easily soluble in water, slightly soluble in ethanol, and the aqueous solution is slightly alkaline. Its thermal stability in aqueous solution is better than that of saccharin, and there is no change when heated at 100°C for 2 hours. When the aqueous solution is left for a long time, the sweetness gradually decreases.