Аннотация:In order to achieve the targeted delivery of Tiosens to a tumor and to overcome the insufficient solubility the liposomal drug form containing egg lecithin, the main component of liposomal bilayer, cholesterol, which provided the durability, and PEG-2000-PE, which protected the liposomal vesicles in the blood stream from capture by reticuloendothelial system cells was studied. The requirements for normalization of liposomal forms of the photosensitizer were justified. Criteria and quality parameters of liposomal forms were established. Experiments on mice with solid Ehrlich tumor revealed high selectivity of accumulation of the photosensitizer in tumors in comparison with normal tissues, and high photodynamic activity of the drug (inhibition of tumor growth achieved 70 - 80 %).