Flavonoids bioavailability assessment using the dissolution test

Reseach is devoted to the study of the bioavailability of flavonoids in in vitro experiments using the Dissolution test in model environments of gastric and intestinal juice. The purpose of the work is a comparative study of the bioavailability of flavonoids using the example of pharmacopoeial-quality rutin and microencapsulated rutin. The concentrations of both fractions (the substance of rutin in the form of a greenish-yellow crystalline powder and microencapsulated rutin) were studied in the gastric and intestinal environment in vitro, followed by the determination of the content of flavonoids by the Folin-Ciocalteu method and the spectrophotometric method. It has been established that rutin begins to dissolve rapidly after 30-40 minutes of being in gastric juice, reaching a concentration of 77.699±3.2 mg/l, thereby being negatively affected by the acidic environment. At the same time, the concentration of rutin in the small intestine becomes lower (the average value of the concentration of rutin in the model environment of intestinal juice is 55.030±3.2 mg/l, and in the environment of gastric juice 59.401±3.2 mg/l). The concentrations of microencapsulated rutin in the gastric environment did not reach high values, while gradually increasing only after 110 minutes of stay in an acidic environment, reaching a value of 75.391±3.2 mg/l. In the intestinal juice medium, the concentrations of microencapsulated rutin were high for 20 minutes, providing its higher bioavailability (the average value of the concentration in the model intestinal juice medium was 90.191±3.2 mg/l). Thus, microencapsulation of rutin made it possible to achieve a prolonged action of the substance, ensuring its preservation in the acidic gastric environment and a sufficiently high release in the intestinal juice medium, where the maximum absorption of nutrients by the intestinal epithelium occurs.