Ionic Liquids: Future Solvents and Reagents for Pharmaceuticals

Abstract

IntroductionRoom temperature ionic liquids (RTILs), an interesting class of tunable and designer solvents with the extremely low vapor pressure have been extensively used as a potential replacement for toxic, hazardous, flammable and highly volatile organic solvents (VOSs) (Welton, 1999;Rogers and Seddon, 2002 Figure 1)), and are liquids at ambient or far below ambient temperatures. In fact, the asymmetry of the cation is believed to be responsible for the low melting temperatures. Based on the solubility of ILs in water, ILs can be divided into two categories: hydrophobic (water immiscible) and hydrophilic (water miscible). This water miscibility generally depends on the anions of ILs. ILs have many attractive physicochemical properties such as negligible vapor pressure, multiple solvation interactions with organic and inorganic compounds (Anderson et al., 2002), excellent chemical and thermal stability (Kosmulski et al., 2004), high ionic conductivity and a wide liquid temperature ranges which draw the growing interest in both industrial and academic research laboratories. Most importantly, the properties regarded as the viscosity, hydrophobicity, density and solubility of ILs can be tuned by selecting different combinations of cations and anions, to customize ILs for specific demands. During the last decade, the interest in the ILs has increased significantly because of their potential as solvents and/or (co)solvents and/or reagents in a wide range of applications, including chemical engineering (separation, extraction and membranes) (Visser et al., 2001;Anderson and Armstrong, 2005)

An Overview on the Toxicological Properties of Ionic Liquids toward Microorganisms

“…They have remarkable features that can be easily custom‐made by a plethora of cations and anions, making them task‐specific solvents and agents. Because of these tailor‐made properties, ILs have been used in a wide variety of applications including biotechnology, chemical engineering, separation processes, material sciences, green chemistry, pharmaceutics, and many others. The use of ILs in biological applications has gained popularity in recent years because ILs are less toxic than that of many conventional organic solvents.…”

Experimental Data of Fluid Phase Equilibria- Correlation and Prediction Models: A Review

“…Research on ILs in pharmaceutical applications has been of great interest in recent years. ILs are useful for changing the kinetic in the delivery system and in general for the increasing of solubility of drugs in water [52][53][54].…”

Recent advances in exploiting ionic liquids for biomolecules: Solubility, stability and applications

“…biocatalysis and biofuel production) [13][14][15][16][17][18], and pharmaceutics (e.g. drug formulation, drug delivery, and formulation of active pharmaceutical ingredients) [19][20][21][22][23][24]. ILs are of particular interest as new and highly efficient solvents/co-solvents/agents for protein-and enzyme-based applications, and they have many advantages over their conventional counterparts (see Box 1).…”