Hydroxypropyl methylcellulose (HPMC) is made of refined cotton after being pulverized, then reacted with sodium hydroxide (liquid caustic soda) solution for alkalization, then added methylene chloride and propylene oxide for etherification reaction, and then passed through medium It is produced in a series of links such as blending, pressing, drying, and screening. It is an odorless, non-toxic white powder that dissolves in water as a clear colloidal solution.