IODINE-POLYURETHANE MATRICES - ANTIMICROBIAL ACTIVITY VS METHOD OF PREPARATION

Polyurethane matrices were prepared by incorporation of iodine during polyurethane polymerization and by immersion of the preformed polymer in iodine solutions. Examination of the IR spectrum has shown that tre atment of the polymer with a concentrated solution of iodine produced structural changes in the polymer. Iodine caused a shift of the N-H st retching band to a lower frequency due to the formation of a complex w ithin an intramolecular hydrogen bonding which takes place between the lone pair electrons of iodine and amine hydrogen. The antimicrobial a ctivity was determined by antimicrobial assay according to the Europea n Pharmacopoeia. The results have shown that, for the same concentrati on of iodine in the polyurethane matrix, a different antimicrobial act ivity is obtained by using the two different methods of preparation. I n patches prepared by the incorporation method, the iodine was strongl y bound to polyurethane. In this case, antimicrobial activity was lowe r than with patches prepared by the immersion method where all iodine was available for antimicrobial activity.