Mechanism of action Hydroxypropyl cellulose is a derivative of cellulose that is soluble in both water and organic solvents. It is particularly good at trapping water and producing a film that serves as a barrier to water loss. Hydroxypropyl cellulose possesses good surface activity but does not gel as it forms open helical coils. In general Hydroxypropyl cellulose is a water-soluble thickener, emulsifier and film-former often used in tablet coating. Indication Used to relieve dryness and irritation caused by reduced tear flow that occurs in certain eye diseases (keratoconjunctivitis sicca), recurrent corneal erosions, decreased corneal sensitivity, exposure and neuroparalytic keratitis, and as a lubricant for artificial eyes.