CONTROL OF THE AMOUNT OF FREE MOLECULAR-IODINE IN IODINE GERMICIDES

Horseradish peroxidase has been used to generate iodine compositions t hat comprised principally free molecular iodine. The concentration of free molecular iodine in these enzyme-based compositions ranged from 4 4 to 63% of the thiosulphate titratable iodine; this is substantially higher than the corresponding value for the povidone-iodine preparatio n betadine. The biocidal efficacy of these compositions was proportion al to the concentration of free molecular iodine. Iodine compositions with relatively low total iodine concentrations but high levels of fre e molecular iodine (20-175 ppm) killed Staphylococcus aureus and spore s of Bacillus subtilis more rapidly than betadine. The effects of norm al saline and these enzyme-based iodine compositions on the rate of ep idermal regeneration in superficial swine wounds were comparable. Thes e results suggest that an effective germicide containing a high level of molecular iodine need not be irritating or toxic.