In order to study its solubility in the gastrointestinal tract in the production environment of "HEPASILIMARIN" capsules, its dissolution test was carefully studied and alternative conditions were selected. Taking into account the importance of using the "in vitro" method, which is the most suitable method in laboratory conditions, practical work was carried out in this method to determine the dissolution test. In performing the experimental part, the equipment of the rotating cajava was used, as specified in the 1st volume of the Pharmacopoeia of the Republic. . Using the equipment, the rate of release of biologically active substances with flavonoid properties contained in the mass of "Hepasilimarin" capsule into the solvent medium, as well as the factor influencing the process of fruitless dissolution, the pH numerical index, were studied. Purified water (pH=5.8), 0.1 molar HCL hydrochloric acid (pH=1.3), sodium bicarbonate NaHCO3as a solvent medium 0.1 molar (pH=8) solution of 0.01 molar sodium tetraborate Na 2 B 4 O 7(pH=9.2) solutions were used. Take it went studies result "in vitro" method is correct for "HEPASILIMARIN" capsules coming The "Reaching" test was developed.