Physical-chemical repurposing of drugs. History of its formation in Russia

It is reported that the traditional scheme of finding and developing a new drug and conducting the whole complex of preclinical studies requires several thousand chemical compounds, hundreds of millions of US dollars and more than 12 years of work. It is shown that physicochemical pharmacology was born in Russia at the end of the 20^th century, which in our days has been transformed into “physicochemical repurposing of known medicines”. The first successfully repurposed known drug was a solution of 4% potassium chloride, which had previously traditionally belonged to the group of macro- and microelements, used by intravenous injections to regulate acid-base balance and rhythmic activity of the heart. In 1983, it was stated that this medicinal solution, when heated to 39–42°C and applied topically by irrigation of the bleeding surface, could be classified as a vasoconstrictor and hemostatic drug. Hyperthermia was used as a physico-chemical reprofiling factor, which, according to the Arrhenius law, accelerated and intensified, on the one hand, the spastic action of K⁺ cations on the gaping blood vessels (formation of hyperkalium contracture in the smooth muscles of the vascular wall) and, on the other hand, the blood clotting process in the wound. In subsequent years, the promise of physicochemical repurposing of known drugs was shown on the example of water, hydrogen peroxide, sodium chloride and sodium bicarbonate by purposefully changing their temperature, acid, osmotic activity, as well as the amount and quality of gas content (passing). A chronology of the physicochemical repurposing of known drug solutions and tablets is described and the essence of such new groups of drugs as bleachers of bruises and pyolytics is given. It is shown that both groups of drugs were discovered in Russia and are intended for local use to bleach bruises (blood stains) and dissolve thick mucus, sputum, pus, blood clots, meconium and other dense biological tissues containing the enzyme catalase. It is pointed out that the advantage and at the same time the limitation of the known drugs repurposed according to this scheme is their local application, since their new pharmacological activity is caused mainly by the physical and chemical principle of action, which is manifested by local interaction with the selected area of the patient’s organism.