DESCRIPTION

Hydroxypropyl Methylcellulose occurs as a white to off-white, fibrous powder or as granules. It is the propylene glycol ether of methylcellulose in which both the hydroxypropyl and the methyl groups are attached to the anhydroglucose rings of cellulose by ether linkages. Several product types are available that are defined by varying combinations of methoxyl and hydroxypropoxyl content. It is soluble in water and in certain organic solvent systems. Aqueous solutions are surface active, form films upon drying, and undergo a reversible transformation from sol to gel upon heating and cooling, respectively.