Pharmaceutical grade HPMC Hydroxypropyl methylcellulose is white or milky white, odorless, tasteless, fibrous powder or granule, weight loss on drying does not exceed 10%, soluble in cold water but not hot water, slowly in hot water Swelling, peptization, and forming a viscous colloidal solution, which becomes a solution when cooled, and becomes a gel when heated. HPMC is insoluble in ethanol, chloroform and ether. It is soluble in a mixed solvent of methanol and methyl chloride. It is also soluble in a mixed solvent of acetone, methyl chloride and isopropanol and some other organic solvents. Its aqueous solution can tolerate salt (its colloidal solution is not destroyed by salt), and the pH of 1% aqueous solution is 6-8. The molecular formula of HPMC is C8H15O8-( C10H18O6) -C815O, and the relative molecular mass is about 86,000.