Hydroxypropylmethylcellulose
It is a semi-composition, inactive, viscoelastic polymer, often used as a lubricant in ophthalmology
Appearance and properties: white or almost white fibrous or granular powder
Density: 1.39 g/cm3
Solubility: almost insoluble in absolute ethanol, ether, acetone; swelling in cold water into a clear or slightly dirty colloidal solution
Stability: The solid is flammable and incompatible with strong oxidants.
Dissolving function: soluble in water and some solvents, such as ethanol/water, propanol/water in appropriate proportions. The aqueous solution has surface activity. High transparency and stable function. Different standard products have different gel temperatures and solubility changes with viscosity. The lower the viscosity, the greater the solubility. Different standards of HPMC have different functions. The dissolution of HPMC in water is not affected by pH.