TauCl due to its biological properties, has been used in topical treatment of various infections. TauBr shows stronger microbicidal activity than TauCl. TauBr therapeutic effectiveness is limited due to its poor stability. To overcome this disadvantage the stable form of TauBr, namely 612Br was synthesized. Synthesis of 612Br opened new possibilities in application of TauBr in the treatment of inflammatory and infectious diseases. However it was necessary to test whether the chemical modification didn’t alter biological properties of 612Br.The aim of this study was to compare physical, chemical, anti-inflammatory and microbicidal properties of 612Br with those of TauBr and TauCl.Stability of 612Br TauBr and TauCl in various conditions of pH and temperature was investigated. We have also compared the effect of 612Br with that of TauBr and TauCl on cell viability and production of inflammatory mediators by activated murine macrophages and human keratinocytes. 612Br retained anti-inflammatory properties of TauBr.This study proved that synthesis of 612Br didn’t cause the loss of the biological properties of native TauBr. While anti-inflammatory potential of 612Br is similar to that of TauBr, it shows stronger microbicidal activity than TauBr. Biological properties and long term stability make 612Br a promising agent in the local treatment of inflammatory and infectious diseases.