Date of Graduation

Fall 2009


Master of Natural and Applied Science in Biology



Committee Chair

Paul Durham


povidone-iodine, ophthalmic antiseptic, surgical preparation solution, endophthalmitis, bacterial conjunctivitis

Subject Categories



Povidone-iodine is very effective against ophthalmic infectious pathogens. While the current formulation for ophthalmic use is therapeutically beneficial, a major limitation is that the commercially available solution is too acidic to put directly on the eye without an anesthetic prior to use. Thus, development of a povidone-iodine solution at a pH near neutral would be expected to cause minimal eye irritation and would be advantageous to prevent and treat ophthalmic infections worldwide. The goal of my thesis project was to determine the efficacy and stability characteristics of a povidone-iodine solution when adjusted to a near-neutral pH. Initially, formulations showed high antimicrobial activity ranging from 4-8 log reductions against Staphylococcus aureus. Chemical analysis revealed optimal values for pH (6.54-6.59), osmolality (289.5-315), and iodine concentrations. As mandated by the Federal Drug Administration (FDA) the stability of the reformulated samples was tested using a standard accelerated aging protocol. After the equivalent of a one year shelf life, none of the solutions maintained their antimicrobial properties due to solution degradation at the recommended elevated temperatures used to test stability. After further investigations, the FDA method of testing stability was shown to not be a valid technique for testing stability of a povidone-iodine solution. In conclusion, it is likely that reformulation of a povidone-iodine solution to near-neutral pH, if shown to be stable for 2 years at room temperature, will provide a safer, less expensive treatment for eye infections.


© Kara Denise Childers

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