This eye drops is a sterile topical ophthalmic solution containing Alcaftadine. Alcaftadine is an histamine receptor antagonist and inhibitor of the release of histamine from mast cell. It is also a potent histamine H2 and H4 receptor antagonist that has demonstrated anti-inflammatory property. In doing so, antihistaminic effect provides relief from itching associated with early phase of ocular allergic response, whereas mast cell stabilization inhibits the release of mediators such as cytokines and lipid mediators that play a role in late-phase response of allergic conjunctivitis.