Density and Speed of Sound for Dilute Binary and Ternary Mixtures of Gabapentin with Surfactant Ionic Liquids Based on Ethanolamine Laurate in Aqueous Solutions at Different Temperatures
Mohammad Bagheri, Hemayat Shekaari, Masumeh Mokhtarpour, Fariba Ghaffari, Saeid Faraji, Behrang Golmohammadi
Abstract
Ethanolamine-based ionic liquids have emerged as cost-effective and environmentally friendly green solvents with a wide diversity of applications. Extensive research around these solvents was focused on improving pharmaceutical products, leading to the discovery of novel drug formulations and delivery systems containing these ionic liquids. Understanding the intermolecular interactions between drugs and these neoteric solvents is crucial for designing effective processes. Thermodynamic investigations provide deep insights into these interactions and help us selecting suitable solvent system for pharmaceuticals. The density and speed of sound data of mixtures containing gabapentin in aqueous solutions of 2-hydroxyethylammonium laurate, bis-2-hydroxyethylammonium laurate, and tris-2-hydroxyethylammonium laurate were determined over a temperature range of (288.15 to 318.15) K. The apparent molar properties, such as apparent molar volumes, V φ, and apparent molar isentropic compressibility, κ φ, were calculated. It’s worth noting that the V φ and κ φ values increase with both temperature and SAILs concentration, and the order of this increase is as follows: [2-hydroxyethylammonium][Laurate] < [bis-2-hydroxyethylammonium][Laurate] < [tris-2-hydroxyethylammonium][Laurate]. Also, the apparent molar isobaric expansion, E φ 0, and Hepler’s constant were computed from the density data. The experimental V φ and κ φ values has been fitted to the Redlich–Meyer equation in the porpuse of obtaining important quantities such as standard partial molar volume, V φ 0, and partial molar isentropic compression, κ φ 0 .