Physico-chemical and biological properties of Ambroxol under irradiation

Physico-chemical properties of Ambroxol (AM), a potential antioxidant drug from the expectorant class, were investigated by radiation chemical and spectroscopic studies. The pulse radiolysis experiments showed that AM is a good scavenger of the primary water radical species, particularly eaq/- and ·OH radicals. The ·OH attack, preferentially addressed to the ring positions activated by the -NH2 group and occupied by bromine atoms, leads to hydroxycyclohexadienyl radicals. The molecule stabilisation may be achieved by a dehalogenation reaction to give phenoxyl radicals. The ·OH attack to AM is not affected by Cu(II) ions, which interact only weakly with the drug as evidenced by IR and Raman spectroscopy. Survival experiments on E. coli B/r cells irradiated in the presence of AM showed a radiosensitising effect of AM in anoxia. Some possible mechanisms of radiosensitisation are outlined.