Solubility of pharmaceutical compounds in ionic liquids

Solubility Data as a Response for a Challenge for Formulation Chemists: Imidazolium-Based Ionic Liquids and Antitubercular Antibiotic Medicines

“…Tables and show the solid–liquid equilibria results, temperatures, T , versus x 1 (mole fraction of the solute), for the studied systems. The commonly discovered result is confirmed in this study, namely a slight increase of temperature leads to a slight increase of solubility. ,− The presented phase diagrams are theoretical solid–liquid phase envelopes. The experimental method did not allow a determination of the eutectic points.…”

“…Because of the diverse nature of ILs, these can have several potential interactions with the compounds, namely Coulombic, dispersive, hydrogen bonding, π–π, n−π, dipolar, and ionic/charge–charge. Nevertheless, in previous studies it has been concluded that the major factors affecting the solubility are the polarity of the ionic liquids and their ability to form hydrogen bonds. ,− Isoniazid being a more hydrophilic compound exhibits enhanced solubility in hydrophilic ILs, that is, negative deviations from ideality, while pyrazinecarboxamide, being slightly less hydrophilic than isoniazid, exhibits enhanced solubility even in slightly more hydrophobic ILs, such as the ones with trifluoromethanesulfonate, but not for highly hydrophobic ILs, such as [C 10 mim]­[OTf] . In this work, the experimental solubility data provided for pharmaceutical and bioactive compounds are described by correlation equations with an adequate σ T .…”

“…The solubility of TB medicines, such as pyrazinecarboxamide (IUPAC name: pyrazine-2-carboxamide) and isoniazid (IUPAC name: isonicotinohydrazide) have been reported for ammonium, phosphonium, , and some imidazolium ,, ILs. This work aimed to provide more solubility data on two antibiotic medicines used in the treatment of TB, namely pyrazinecarboxamide and isoniazid, in several ILs composed by imidazolium cations, to see the effect of the anion (tetrafluoroborate [BF 4 ], hexafluorophosphate [PF 6 ], trifluoromethanesulfonate [OTf]), as well as influence of the alkyl chain length of the cation by investigating 1-alkyl-3-methylimidazolium trifluoromethanesulfonate [C n mim] [OTf], ( n = 4, 8) and comparison with n = 10. , The molecular structures for the antitubercular compounds and the ionic liquids that were used in this work are presented in Figure .…”

Green Solvents Combined with Bioactive Compounds as Delivery Systems: Present Status and Future Trends

“…The oil–water emulsion formed by the [Ch]­[Ole] dissolution allows the curcumin to be in the oil phase. Moreover, other compounds, such as coumarin, N -acetyl- l -cysteine, and 4-hydroxycoumarin, with known therapeutic effects, were successfully dissolved in ILs . dos Santos et al discovered that the best solvent for the dissolution of N -acetyl- l -cysteine and 4-hydroxycoumarin was 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([C2mim]­[OTf]).…”

Solubility of Bioactive, Inorganic and Polymeric Solids in Ionic Liquids — Experimental and Prediction Perspectives

“…Results obtained allowed to conclude that ammonium ILs are better solvents than imidazolium, even imidazolium triflate. Finally Bogel-Lukasik E. and co-workers[31] extended their investigation to other pharmaceutical compounds, namely, N-acetyl-cysteine, coumarin and 4-hydroxycoumarin. In this case ionic liquids investigated were again imidazolium ILs containing the [NTf 2 ] and [OTf] anions.…”