Solid-State and Solution Characterization of Myricetin

Abstract

Abstract. Myricetin (MYR) is a natural compound that has been investigated as a chemopreventative agent. MYR has been shown to suppresses ultraviolet B (UVB)-induced cyclooxygenase-2 (COX-2) protein expression and reduce the incidence of UVB-induced skin tumors in mice. Despite MYR's promise as a therapeutic agent, minimal information is available to guide the progression of formulations designed for future drug development. Here, data is presented describing the solid-state and solution characterization of MYR. Investigation into the solid-state properties of MYR identified four different crystal forms, two hydrates (MYR I and MYR II) and two metastable forms (MYR IA and MYR IIA). From solubility studies, it was evident that all forms are very insoluble (<5 μg/ml) in pure water. MYR I was found to be the most stable form at 23, 35, and 56°C. Stability determination indicated that MYR undergoes rapid apparent first-order degradation under basic pH conditions, and that degradation was influenced by buffer species. Apparent first-order degradation was also seen when MYR was introduced to an oxidizing solution. Improved stability was achieved after introducing 0.1% antioxidants to the solution. MYR was found to have good stability following exposure to ultraviolet radiation (UVR), which is a consideration for topical applications. Finally, a partitioning study indicated that MYR possess a log P of 2.94 which, along with its solid-state properties, contributes to its poor aqueous solubility. Both the solid-state properties and solution stability of MYR are important to consider when developing future formulations.

Solubility Enhancement of Myricetin by Inclusion Complexation with Heptakis-O-(2-Hydroxypropyl)-β-Cyclodextrin: A Joint Experimental and Theoretical Study

“…The thermogravimetry (TG) and derivative thermogravimetry (DTG) curves for HP-β-CD: myricetin inclusion complex, physical mixture, HP-β-CD, and myricetin are shown in Figure 5. HP-β-CD presented almost no mass loss within the temperature range of room temperature to 300 • C. In addition, HP-β-CD lost 86.86% of its mass in the temperature range of 300-400 • C, with a maximum degradation rate at 347.6 • C. Furthermore, HP-β-CD lost 3.44% of its mass in the temperature range of 400-590 • C. Myricetin displayed a different degradation process of losing 26.08% and 19.19% of its mass in the temperature range of 300-400 • C and 400-590 • C, respectively, with a maximum mass variation rate at 369.9 • C, which is similar to other reports [22].…”

“…Furthermore, HP-β-CD lost 3.44% of its mass in the temperature range of 400-590 °C. Myricetin displayed a different degradation process of losing 26.08% and 19.19% of its mass in the temperature range of 300-400 °C and 400-590 °C, respectively, with a maximum mass variation rate at 369.9 °C, which is similar to other reports [22]. The HP-β-CD: myricetin inclusion complex showed a maximum mass loss rate at 302.65 °C lower than that of the physical mixture at 317.83°C.…”

Chemoprevention of intestinal tumorigenesis by the natural dietary flavonoid myricetin inAPCMin/+mice

“…Myricetin (purity ≥ 96%) was purchased from Sigma Chemical Co (St. Louis, MO). The chemical structure 3,5,7,3′,4′,5′-hexahydroxyflavone was described elsewhere [ 43 , 44 ]. Myricetin was dissolved in 5% sodium carboxymethyl cellulose (CMC-Na) (Sigma Chemical Co).…”

Flavonoids with Glutathione Antioxidant Synergy: Influence of Free Radicals Inflow

“…These flavonoids are well-known natural antioxidants whose potential health benefits have attracted a great deal of interest in their studies as prospective drugs [ 7 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. Thus, a large and growing body of literature has been devoted to the modification of their biopharmaceutical and physicochemical properties, such as antioxidant activity and bioavailability, by crystal engineering [ 40 , 41 , 42 , 43 , 44 ], obtaining solid dispersions [ 45 , 46 , 47 , 48 , 49 ], and the development of new polymorphic forms [ 50 , 51 , 52 , 53 , 54 ]. This report is in line with the abovementioned works and aims to study the possible alteration of the antioxidant activity of flavonoids by combining them with other natural antioxidants.…”