The present invention relates to pharmacology, medicine, veterinary science and pharmaceutical industry, namely to pharmaceutical compositions for the preparation of infusion solutions of antimicrobial preparations potentiating the therapeutic efficacy of antimicrobial medicaments, during the process of preparing solutions thereof immediately before carrying out intravenous infusions and the process of producing original composite pharmaceutical ingredients. The claimed pharmaceutical compositions for the preparation of injection solutions of all the tested antimicrobial preparations comprising the finely dispersed powder of nanostructured colloidal silica, reliably increase their therapeutic efficacy when treating generalised sepsis in test animals, provoked by Staphylococcus aureus, Escherichia coli, Pseudo-monas aeruginosa and Candida albicans. The claimed pharmaceutical compositions for the preparation of antibacterial and antifungal preparations solutions for intravenous infusions (NaCl : Colloidal silica and Dextrose : Colloidal silica) have a significant clinically sginificant potentiating action on their therapeutic potential when treating inflammatory infectious disease, in comparison with traditional solvents (prototypes of the invention).