Hydroxypropyl methylcellulose (HPMC), is a semisynthetic, inert, viscoelastic polymer used as eye drops, as well as an excipient and controlled-delivery component in oral medicaments, found in a variety of commercial products.
(Hydroxypropyl)methyl cellulose (HPMC), an inert viscoelastic polymer is used as an emulsifier, thickening and suspending agent similar to animal gelatin.