(Hydroxypropyl)methyl cellulose-viscosity 80-120cP CAS 9004-65-3

Hydroxypropyl methylcellulose (HPMC or Hypromellose) is a semisynthetic, inert, viscoelastic polymer used as eye drops, as a semisynthetic substitute for tear-film. When applied, a hypromellose solution acts to swell and absorb water, by increasing the thickness of the tear-film resulting in decreased eye irritation.  In addition to its use in ophthalmic liquids, hypromellose has been used as an excipient in oral tablet and capsule formulations, where, depending on the grade, it functions as controlled release agent. It is also used as a binder and as a component of tablet coatings.  Hypromellose in aqueous solution, unlike methylcellulose, exhibits thermal gelation properties.   HPMC is approved as a food additive as an emulsifier, thickening and suspending agent, and an alternative to animal gelatin (Codex Alimentarius code (E number) is E464).