Solid-phase product based on dihydroquercetin and glycine: preparation and physico-chemical properties

Introduction. Alzheimer's disease is the most common cause of dementia and imposes a heavy financial burden on society in developed countries. According to scientific information, flavonoids prevent the formation of β-amyloid plaques and tau aggregates, proteins that play a key role in the pathogenesis of Alzheimer's disease. To overcome the biopharmaceutical limitations of flavonoids, it is proposed to obtain crystals with amino acids. Assuming a possible pharmacological synergism, the amino acid glycine, which is also capable of influencing links in the biochemical mechanisms of neurodegenerative diseases, was chosen as a conformer to dihydroquercetin flavanonol. Objective is to obtain and to characterize a solid-phase product of dihydroquercetin and glycine. Material and methods. The dihydroquercetin-glycine composition was obtained by lyophilization of their aqueous solution. The morphology was characterized by scanning electron microscopy. The crystallinity was demonstrated by X-ray powder diffraction spectra. The thermal analysis was performed by differential scanning calorimetry and thermogravimetry. The solubility in water was evaluated, according to SP RF XV. Results. Lyophilizate is a light-yellow powder. The form of these particles is thin flakes with a perforated surface, which have a significantly lower degree of crystallinity compared to the initial components. Crystallization of the amorphous flavonoid impurity in the composition is not observed, but we can see the phase transition from γ-glycine to α-glycine. According to SP RF XV, the solubility of resulting product is more than raw dihydroquercetin. Conclusion. The solid monophase dihydroquercetin-glycine system can be used to develop a new dosage form “Lyophilizate” (SP RF XV, PM.1.4.1.0031) and further preclinical study of safety and efficacy of neurodegenerative diseases.