Environmental pollution is one of the most pressing problems facing humanity. The constant search for its solution is an important aspect of modern chemistry. The work studied the oxidative degradation of two antibiotics of the same pharmaceutical group, with a similar structure but diff erent properties. The purpose of this work was to study the oxidation process of the active substances of two antibiotics: tetracycline and doxycycline by various oxidative and combined systems: the Fenton system, the Ruff system, their combined action, their action in the presence of EDTA, as well as under the action of UV irradiation. The conducted studies have shown that under conditions of room temperature and normal atmospheric pressure, hydrogen peroxide in combination with iron (II) and (III) ions is able to oxidize the active components of tetracycline and doxycycline. The optimal conditions for the oxidation of the tetracycline group of antibiotics have been determined: the concentration of the substrate, hydrogen peroxide, iron (II) ions, iron (III) ions, and the pH of the reaction. It has been shown that the combined presence of iron (II) ions and iron (III) ions in the system reduces the consumption of hydrogen peroxide during the oxidation of active substances of tetracyclines. It has been shown that the replacement of hydrated iron ions with iron complexes with EDTA has a slight eff ect on the oxidation effi ciency of tetracycline and doxycycline. It has been revealed that iron (III) complexes with EDTA are more eff ective in the destructive process of tetracycline. It has been established that the active substance of tetracycline preparations undergoes destruction under the action of UV irradiation. It is shown that photodestruction reactions of active substances of tetracyclines are reactions of the fi rst order. The rate constants of these processes are determined. It has been revealed that the destruction of doxycycline proceeds most fully under the action of the Raff system, as well as under the action of UV irradiation in the presence of hydrogen peroxide. It is shown that the studied oxidative systems are eff ective for the destruction and inactivation of pharmaceutical pollutants belonging to the tetracycline group.