In vitro Evaluation of Skin Sensitivity of Povidone-Iodine and Other Antiseptics Using a Three-Dimensional Human Skin Model

Povidone-iodine (PVP-I) is an antiseptic which has been widely used in various fields. It was reported to have a weaker skin irritancy than other antiseptics in the Draize skin irritation test using rabbits. Recent increased concern for animal welfare requires us to use skin models in the tests as an alternative to animal testing. Actually, there are some skin models already commercialized, which are available to evaluate skin irritancy caused by e.g. chemical reagents, cosmetics or medicines. In this study, we evaluated the potential of a PVP-I solution and other antiseptics to cause irritation using a cultured human skin model (three-dimensional skin model) under conditions similar to clinical use. This skin model has two layers like a real skin, such as the dermis and epidermis which includes the cornified layer. For the evaluation of skin irritancy in this model, cell viability was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay as an endpoint. Antiseptic formulations such as benzalkonium chloride (BAC), benzethonium chloride (BEC), chlorhexidine gluconate (CHG) and alkyldiaminoethylglycine hydrochloride (AEG) were used in this study. As a result, PVP-I showed a significantly weaker skin irritancy compared to the other antiseptics. The present in vitro study results revealed a correlation with the results of previously conducted in vivo skin irritancy tests using rabbits.