Investigate the significance of DES to enhance the solubility of noscapine: DFT calculations, MD simulations, and experimental approach

In the present work, investigation of the choline chloride-urea base deep eutectic solvents (DES) in various solvents has been performed to explore the change in interaction between choline chloride and urea. A comparative study of various thermodynamic and physiochemical properties of DES in different solvents have been conducted. TD-DFT of the designed DES was performed in different solvents to understand variation in the electronic transition. Further, the DES was explored to enhance or improve the solubility of a drug like candidates, that is, noscapine (NOS). Noscapine is being used as a cough suppressant and possesses anti-cancer potential. It was observed chloride ion of the choline chloride (HBA) showed the huge non-covalent interactions, that is, hydrogen bond, electrostatic, and van der Waals interaction with the hydrogen the donor (HBD) urea. The number of interactions were found to be higher in the polar solvents than in non-polar solvents. The overall stability was also found to be higher in polar solvents. In studying the solubility of NOS in DES through DFT, calculation showed an increase in dipole moment. Therefore, DES could be used to enhance the solubility of the noscapine. Further, molecular dynamics simulations of NOS, DES, and the complex have been performed for 100 ns to understand the stability of the complex. Root mean square deviation (RMSD) and root mean square fluctuation (RMSF) trajectories are in the acceptable range and indicated the formation of stable complex between DES and noscapine. Graphical abstract