Abstract: A pharmaceutical formulation that is effective in adversely affecting the viability of microorganisms or in inhibiting their growth and that provides better safety and/or comfort to the users comprises a polysaccharide, a source of hydrogen peroxide, and an anti-oxidant. The formulation can further comprise a chelating agent and/or an ophthalmically active agent for treating or controlling a disease or disorder of the eye. The formulation may be used to treat, clean, disinfect, store, wet, or rewet contact lenses.