Abstract: Benzimidazole derivatives having general formula (I), wherein R.sub.1 and R.sub.2 are a hydrogen atom, a lower alkyl radical, an OR.sub.4 radical, a lower fluoroalkyl radical or a halogen atom; R.sub.3 is a hydrogen atom, a lower alkyl radical, a halogen, a hydroxyl or a lower alkoxy radical having 1-6 carbon atoms; R.sub.4 is a hydrogen atom, a lower alkyl radical, a benzyl radical or a (II) radical, PO.sub.3 H, SO.sub.3 H or an aminoacid residue; R.sub.7 is a lower alkyl radical, a lower alkoxy radical having 1-6 carbon atoms, a --(CH.sub.2).sub.n --COOH radical where n=1-6, or the radical (III), where r' and r" are a hydrogen atom or a lower alkyl radical, or form, together with the nitrogen atom, a 5 or 6-membered heterocyclic ring optionally interrupted by a heteroatom; R.sub.5 and R.sub.6 are different and represent the OR.sub.8 radical or a mono or polycyclic cycloalkyl radical having 5-12 carbon atoms bound to the phenyl core by a tertiary carbon; R.sub.