Hydroxypropyl methylcellulose (HPMC) is a white or off-white fibrous powder or granules with excellent cold-water solubility. As a nonionic cellulose ether, HPMC is uncharged in aqueous solution, resulting in strong stability and good compatibility with other excipients or APIs. Toxicological studies have shown that it is not metabolized in the body and has no toxic side effects, making it a safer pharmaceutical excipient. Due to its varying molecular weight and viscosity, it possesses properties such as bonding, thickening, suspending, emulsifying, and film-forming properties, resulting in its wide application in pharmaceutical formulations. It is often used as a binder, dispersant, thickener, film coating material, and sustained-release matrix material in pharmaceutical formulations.