Hypromellose is used as a drop where not enough tears are produced to keep the eye moist & clean. Hypromellose lubricates the surface of the eye just as natural tears do, so it can be used to relieve the dryness & pain associated with reduced or abnormal tear production. What is it used for? Reduced or deficient tear production Isopto Alkaline is supplied in a 10 ml bottle containing 10 mg of hypromellose in every ml of solution. It also contains 0.1 mg of Benzalkonium chloride in each ml of solution as a preservative. Other ingredients include Sodium citrate, Sodium Phosphate, Sodium biphosphate, Sodium chloride & Purified water. This medicine should not be used if your pet is allergic to one or any of its ingredients.