Natural Deep Eutectic Solvents as Agents for Improving Solubility, Stability and Delivery of Curcumin

Abstract

Purpose Study on curcumin dissolved in natural deep eutectic solvents (NADES) was aimed at exploiting their beneficial properties as drug carriers. Methods The concentration of dissolved curcumin in NADES was measured. Simulated gastrointestinal fluids were used to determine the concentration of curcumin and quantum chemistry computations were performed for clarifying the origin of curcumin solubility enhancement in NADES. Results NADES comprising choline chloride and glycerol had the highest potential for curcumin dissolution. This system was also successfully applied as an extraction medium for obtaining curcuminoids from natural sources, as well as an effective stabilizer preventing curcumin degradation from sunlight. The solubility of curcumin in simulated gastrointestinal fluids revealed that the significant increase of bioavailability takes place in the small intestinal fluid. Conclusions Suspension of curcumin in NADES offers beneficial properties of this new liquid drug formulation starting from excreting from natural sources, through safe storage and ending on the final administration route. Therefore, there is a possibility of using a one-step process with this medium. The performed quantum chemistry computations clearly indicated the origin of the enhanced solubility of curcumin in NADES in the presence of intestinal fluids. Direct intermolecular contacts leading to hetero-molecular pairs with choline chloride and glycerol are responsible for elevating the bulk concentration of curcumin. Choline chloride plays a dominant role in the system and the complexes formed with curcumin are the most stable among all possible homo- and hetero-molecular pairs that can be found in NADES-curcumin systems.

Efficacy of Natural Deep Eutectic Solvents for Extraction of Hydrophilic and Lipophilic Compounds from Fucus vesiculosus

“…The stability of TPhC in the extracts (Figure 6a) was correlated with the antioxidant activity (Figure 6b). Our results are in agreement with literature data in which NADES provides better stability for carthamin [76], anthocyanins [69], and curcumin [15]. The stabilization ability of NADES may have a direct relationship to their viscosity [76].…”

“…This leads to a reduction in the contact time for metabolites on the NADES surface with air and consequently resulted in less oxidative degradation [69]. Additionally, oxygen has a lower solubility in NADES than in ethanol Our results are in agreement with literature data in which NADES provides better stability for carthamin [76], anthocyanins [69], and curcumin [15]. The stabilization ability of NADES may have a direct relationship to their viscosity [76].…”

“…To be predominantly polar liquids, NADES have been used for the extraction of alkaloids [6], anthocyanins [7][8][9], glycosides of phenyletanes and phenylpropanoids [10], and polysaccharides [11]. NADES could be customized for the extraction of less polar aglycones of flavonoids [12], anthraquinones [13], astaxanthin [14], curcumin [15], glycyrrhizic acid [16], iridoids [17], and steroidal saponins [18]. Hydrophobic terpenes and fatty acid-based NADES allowed for the isolation of carotenoids, free fatty acids, and pheophytin [19].…”

Thermodynamics and Intermolecular Interactions of Nicotinamide in Neat and Binary Solutions: Experimental Measurements and COSMO-RS Concentration Dependent Reactions Investigations

“…This observation is valid for all systems in the whole range of concentrations, except methanolic solutions in the diluted range of x 2 < 0.5. The strong influence of the level of quantum chemistry computations on the predicted values of the Gibbs free energy of reactions involving solutes and solvent molecules has already been documented [ 56 , 57 ]. This suggests that final conclusions regarding the mutual affinities of studied systems should be drawn based on a more advanced level of computation.…”

Simultaneous Natural Deep Eutectic Solvent-Based Ultrasonic-Assisted Extraction of Bioactive Compounds of Cinnamon Bark and Sappan Wood as a Dipeptidyl Peptidase IV Inhibitor

“…To obtain beneficial effects from natural products, an extraction strategy is needed [ 11 ]. Based on conventional solvents comparisons, the use of a natural deep eutectic solvent (NADES) has some advantages: it is biodegradable, non-toxic, non-volatile, not frozen at low temperatures, has high extraction ability, a relatively low price, and simple preparation [ 12 , 13 ]. Besides that, the use of the ultrasonic-assisted extraction (UAE) method is one of the non-conventional extraction methods that can extract target secondary metabolites with high reproducibility, shorter extraction times, and minimal solvent use [ 14 ].…”