Background. Increasing the solubility of new pharmacologically active substances is one of the main tasks of pharmacy. It becomes even more relevant in the field of creating dosage forms for difficult-to-solubilise substances with a new mechanism of action, as in the case of 3-hydroxyquinazoline derivatives, which have shown in vivo experiments the ability to activate tumour cell death by ferroptosis. This includes OVF-009 – an original domestic substance. Due to the solubility of this compound in oils, the technology of its solubilisation using modified castor oil (Kolliphor® ELP, BASF, Germany), approved for parenteral use, was proposed.Aim. To create a model dosage form for a new hydrophobic quinazoline derivative in order to further evaluate the spectrum of its antitumour activity in in vivo experiments.Materials and methods. OVF-009, Kolliphor® ELP, 95 % ethanol, Kollidon 17 PF (BASF, Germany), sodium hydroxide, phosphate buffer, water for injection; spontaneous micelle formation, ultrasound, potentiometry, dynamic light scattering, electrophoretic method, viscometry method, etc.Results. The main properties of micelle-forming solubiliser Kolliphor® ELP and its aqueous solutions were considered; 10 model solutions OVF-009 based only on Kolliphor® ELP and with addition of ethanol and Kollidon 17PF in different concentrations were obtained; the quality of the obtained compositions was evaluated by parameters – appearance, solution transparency, pH, stability over time and tolerability by laboratory animals. As a result, two formulations prepared on phosphate buffer were chosen: formulation No 5, which contains 10 % Kolliphor® ELP and additionally 10 % polyvinylpyrrolidone, and formulation No 8, in which in addition to the main solubiliser 10 % ethanol and 16 % polyvinylpyrrolidone were added. Both formulations have neutral pH, can be stored for 24 h and are tolerated by laboratory animals.Conclusion. The selected model compositions for solubilisation of the substance OVF-009 on the basis of Kolliphor® ELP allowed to provide the concentration of the active substance in the solution suitable for further biological experiments on animals.