bacitracin zinc + polymyxin b sulfate + gramicidin

This is a combination antibiotic formulation containing three active ingredients: **bacitracin zinc**, **polymyxin b sulfate**, and **gramicidin**. It is used primarily as an ophthalmic solution to treat bacterial infections of the eye and eyelids, such as conjunctivitis and blepharitis. Bacitracin inhibits cell wall synthesis in susceptible bacteria, polymyxin b disrupts bacterial cell membrane integrity primarily in Gram-negative organisms, and gramicidin increases cell membrane permeability in bacteria, leading to cell death. This combination covers both Gram-positive and Gram-negative organisms for topical ophthalmic infection treatment[7][4].