Azo-derivatives pharmaceutical preparations containing them and their use against aids

Compositions useful in methods of disinfecting contain azoic compounds of the general formula wherein R1, R2, R3 and R4 are identical or different and each represents an atom of hydrogen or an aliphatic or aromatic hydrocarbon radical comprising from 1 to 6 carbon atoms; X1 and X2 are identical or different and each represents an oxygen atom or an NR5 group, wherein R5 is a hydrogen atom, an aliphatic or aromatic hydrocarbon radical comprising from 1 to 6 carbon atoms, or a nitro group; and wherein when two NR5 groups are simultaneously present each R5 may be identical to or different from the other. Compositions containing the azoic compounds in a liquid medium at concentrations of from 35 mu gr/ml to 2 mgr/ml are sufficient to impede replication and proliferation of viruses of the retrovirus group yet they are insufficiently toxic to destroy sound human or animal cells which come in contact with the compositions. Methods of disinfecting using the compositions are also provided.