Interaction of povidone-iodine compounds, phagocytic cells, and microorganisms

The interaction between povidone-iodine, phagocytic cells, and microorganisms was studied. Three preparations of povidone-iodine were investigated: commercially available povidone-iodine solution Betadine, pure high-molecular-weight povidone-iodine as used in Betadine, and a low-molecular-weight povidone-iodine. Low concentrations of povidone-iodine (approximately 0.005%) have considerable activity in vitro. The concentrations used clinically (0.1 to 20%) are toxic for granulocytes and monocytes. Leukocytes reduce the in vitro microbicidal activity of povidone-iodine. No differences of any importance were found between the three preparations of povidone-iodine.