Lack of in vitro Genotoxicity of Povidone-Iodine in Solution, in Ointment or in a Liposomal Formulation (Repithel®)

Abstract

The in vitro genotoxicity of povidone-iodine in Repithel^®, Betaisodona^® ointment and Betaisodona^® solution was investigated using CHO-K1 cells. The comet assay and chromosome aberration test were used to characterise the genotoxic potency of povidone-iodine within 4 h of contact with test cells. Methyl methanesulphonate without S9 activation and benzo[a]pyrene with S9 activation were used as positive controls. No higher concentrations than 6% Repithel, 5% Betaisodona ointment and 2% Betaisodona solution in culture medium with 10% fetal bovine serum were tested within 4 h of contact with CHO-K1 cells for the comet assay, because higher concentrations will provide >60% cytotoxicity. All tested concentrations of povidone-iodine formulations (4–6% Repithel, 3–5% Betaisodona ointment and 1–2% Betaisodona solution) are not genotoxic in the comet assay. 10% Repithel, 5% Betaisodona ointment and 2.5% Betaisodona solution in culture medium with 10% fetal bovine serum were final concentrations in the chromosome aberration test, which provide <60% cytotoxicity within 4 h of contact with CHO-K1 cells. All tested concentrations of povidone- iodine formulations (5–10% Repithel, 2.5–5% Betaisodona ointment and 1.25–2.5% Betaisodona solution) are not genotoxic in the chromosome aberration test. Using the comet assay and chromosome aberration test to characterise the genotoxic potency of povidone-iodine within 4 h of contact with CHO-K1 cells, there was no chromosome damage detected.