Pre-clinical toxicologic studies were conducted of a new drug teraphtal-Lio (TPh) and a teraphtal-Lio + ascorbic acid (TPh + AA) catalytic system recommended for binary catalytic therapy of malignant tumors. Quantitative criteria for "acute" and "chronic" toxicity of TPh and TPh + AA were established, which describe their toxic effects in single or multiple application. The coefficient of specific sensitivity and cumulation index for TPh and TPh + AA were determined. The toxicodynamic characteristics of TPh and TPh + AA were investigated. The results were used to prognose pulmonary, cardio-vascular, hemato- and hepatotoxic as well as hemodynamic and ophthalmologic disorders and functional changes in the central nervous system involved in clinical use of TPh and TPh + AA.