Chemical name: (2-mercaptoethyl) trimethylammonium iodide O,O-diethyl phosphorothioate

Structural formula

Echothiophate iodide for ophthalmic solution occurs as a white, crystalline, water-soluble, hygroscopic solid having a slight mercaptan-like odor. When freeze-dried in the presence of potassium acetate, the mixture appears as a white amorphous deposit on the walls of the bottle.

Each package contains materials for dispensing 5 mL of eyedrops: (1) bottle containing sterile echothiophate iodide for ophthalmic solution 6.25 mg (0.125%) with 40 mg potassium acetate. Sodium hydroxide or acetic acid may have been incorporated to adjust pH during manufacturing; (2) a 5 mL bottle of sterile diluent containing chlorobutanol (chloral derivative), 0.55%; mannitol, 1.2%; boric acid, 0.06%; and sodium phosphate, 0.026%; (3) sterilized dropper.