Apigenin Solubility in Choline-Chloride and Polyol Based Eutectic Solvents

Apigenin (API) is a natural plant flavonoid with anti-inflammatory and cytotoxic properties, whose therapeutic application is often limited by poor water solubility. The aim of this study was to evaluate the solubility of apigenin in various choline chloride (ChCl) and polyol (sorbitol (SOR), xylitol (XYL), mannitol (MAN), sucrose (SUC), isomalt (ISOM) based eutectic solvents. The use of eutectic systems represents an environmentally friendly alternative to conventional organic solvents and may enhance the solubility and bioavailability of poorly soluble compounds.
Method
Samples were prepared by the shake-flask method, mixing 500 mg of ChCl with different polyols in corresponding ratios, and adding 100 mg of apigenin, with varying water content (0-25% v/v). The mixtures were incubated for 24 hours in Eppendorf (DNA LoBind Tube 1.5mL) tubes and mixed using magnetic stirring (10 mm stir bars) at 60-80 °C depending on polyol. After incubation, the samples were centrifuged (Hermle LaborTechnik GmbH - Z 160 M Microlitre Centrifuge) for 25 minutes at maximum rotation speed, and 25 mg aliquots of the lower layer were diluted in 10 mL of mobile phase consisting of 55% acetonitrile and 45% 0.1% formic acid solution. From this solution, 200 μL were taken and diluted to a final volume of 1 mL using the mobile phase.
Apigenin solubility was determined using a Thermo Scientific Vanquish HPLC system. The analysis was performed at a flow rate of 1 mL/min on a C18 Zorbax column at chamber temperature 35oC. The apigenin amount was measured at 269 nm and 335 nm wavelength UV light. Each water content variant was prepared in triplicate, and results were expressed as mg of apigenin per gram of solvent.
Data
The dataset contains the experimental data and results of the solubility of apigenin in different choline chloride–polyol deep eutectic solvents with different water content (0-25%), along with representative HPLC chromatogram pictures. The data were processed using Chromeleon 7.3.1 Chromatography Data System (Thermo Fisher Scientific) and compiled in an Excel spreadsheet format.