... as doxorubicin free base, its greater water solubility may offer advantages in some in vitro applications. Physicochemical properties ... non-pH controlled systems the free base and salt may behave differently. Air & Water Reactions Water soluble. Reactivity ... plus water. These acid-base reactions are exothermic. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols ( ...