Quercetin/β-Cyclodextrin Solid Complexes Prepared in Aqueous Solution Followed by Spray-drying or by Physical Mixture

Abstract

Abstract. The present study was designed to investigate the influence of operating conditions (temperature, stirring time, and excess amount of quercetin) on the complexation of quercetin with β-cyclodextrin using a 2 3 factorial design. The highest aqueous solubility of quercetin was reached under the conditions 37°C/24 h/6 mM of quercetin. The stoichiometric ratio (1:1) and the apparent stability constant (Ks=230 M −1 ) of the quercetin/β-cyclodextrin complex were determined using phase-solubility diagrams. The semi-industrial production of a 1:1 quercetin/β-cyclodextrin solid complex was carried out in aqueous solution followed by spray-drying. Although the yield of the spray-drying process was adequate (77%), the solid complex presented low concentration of quercetin (0.14%, w/w) and, thus, low complexation efficiency. The enhancement of aqueous solubility of quercetin using this method was limited to 4.6-fold in the presence of 15 mM of β-cyclodextrin. Subsequently, an inclusion complex was prepared via physical mixture of quercetin with β-cyclodextrin (molar ratio of 1:1 and quercetin concentration of 23% (w/w)) and characterized using infrared spectroscopy, differential scanning calorimetry, nuclear magnetic resonance spectroscopy, and scanning electron microscopy analyses. The enhancement of aqueous solubility of quercetin using this method was 2.2-fold, similar to that found in the complex prepared in aqueous solution before the spray-drying process (2.5-fold at a molar ratio of 1:1, i.e., 6 mM of quercetin and 6 mM of β-cyclodextrin).

Quercetin solid lipid microparticles: A flavonoid for inhalation lung delivery

“…The DSC thermogram of quercetin raw material exhibited an endothermi c peak at 321 °C, typical of melting, in line with literature data (Borghetti et al, 2009 ). Another smaller endothermic peak is visible at around 137 °C related to a decompo sition process with water loss (Da Costa et al, 2002 ).…”

Preparation of metal doped quercetin nanoparticles, characterization and their stability study

“…2). Some reports informed the existence of anhydrous and dihydrate nature of quercetin and XRD analysis was done for in-depth information on both morphological and surface properties of quercetin [24,25]. XRD pattern of QNPs is shown in Fig.…”

Phase Solubility Study of Quercetin in Presence of Cyclodextrins and Hydrophilic Polymers.

“…Most of therapeutic benefits of QUN are related to its antioxidant activity. QUN also shows antihypertensive, antiobesity, antihypercholesterolemic and antiatherosclerotic activities [1][2][3][4]. Despite of these benefits, it is observed that QUN shows poor bioavailability when administered orally, due to its poor solubility [5].…”