Physico-chemical characterization of coamorphous modifications based on dihydroquercetin and L-lysine

Introduction. Dihydroquercetin (DHQ) is a flavonoid that is characterized by limited bioavailability, that particularly associates with low solubility in water under normal conditions. Previously, DHQ was combined with the proteinogenic amino acid L-lysine to create a composition that exhibited strong anti-inflammatory and wound healing effects in models of grade III burn injuries in rats. Objective: To obtain and characterize solid monophasic systems based on DHQ and L-lysine using a complex of physico-chemical methods. Material and methods. To obtain DHQ compositions containing L-lysine, grinding techniques were used with the following lyophilization or drying of the aqueous solution at 65 °C. Scanning electron microscopy was employed to examine the microstructure of the resulting objects. The structure and properties of the solid phase were characterized using X-ray powder diffraction and thermal analysis methods. The chemical composition was analyzed using infrared spectroscopy and nuclear magnetic resonance methods. Quantitative analysis was performed using high performance liquid chromatography (HPLC). Results. Coamorphous modifications based on DHQ and L-lysine, in the form of films and mesoporous lyophilizates, have been obtained and characterized using physico-chemical methods. No formation of new covalent bonds between the components during the preparation of these modifications was observed. A glass transition effect at a temperature of 64 °C was detected for the films. To monitor the quantitative composition of the components, a method based on HPLC with pre-column derivatization using o-phthalaldehyde and UV-detection was developed. Conclusion. Thus, the obtained objects are coamorphous systems in the form of glass-like film and porous materials formed through intermolecular interactions between DHQ and L-lysine. In the future, it will be interesting to develop dosage forms based on these objects