TY - JOUR

T1 - Active Pharmaceutical Ingredient-Ionic Liquids (API-ILs): Nanostructure of the Glassy State Studied by Electron Paramagnetic Resonance Spectroscopy

AU - Bakulina, Olga D.

AU - Ivanov, Mikhail Yu

AU - Alimov, Dmitriy V.

AU - Prikhod'ko, Sergey A.

AU - Adonin, Nicolay Yu

AU - Fedin, Matvey V.

N1 - Publisher Copyright: © 2022 by the authors.

PY - 2022/8/11

Y1 - 2022/8/11

N2 - Active Pharmaceutical Ingredient-Ionic Liquids (API-ILs) draw increasing interest as a particular class of ILs that possess unusual physicochemical properties along with simultaneous potentials for pharmaceutical applications. Although nanostructuring phenomena were actively investigated in common ILs, their studies in API-ILs are scarce so far. In this work, using the complex methodology of Electron Paramagnetic Resonance (EPR) and dissolved spin probes, we investigate nanostructuring phenomena in a series of API-ILs: [Cnmim][Ibu], [Cnmim][Gly], and [Cnmim][Sal] with n = 2, 4, and 6, respectively. We reveal similar trends for API-ILs and common ILs, as well as peculiarities inherent to the studied API-ILs. Unusual behavior observed for [Cnmim][Ibu] has been assigned to the presence of a non-polar fragment in the [Ibu]- anion, which leads to the formation of more complex nanostructures around the radical compared to common ILs. Understanding general trends in the formation of such self-organized molecular structures is of fundamental interest and importance for applying API-ILs.

AB - Active Pharmaceutical Ingredient-Ionic Liquids (API-ILs) draw increasing interest as a particular class of ILs that possess unusual physicochemical properties along with simultaneous potentials for pharmaceutical applications. Although nanostructuring phenomena were actively investigated in common ILs, their studies in API-ILs are scarce so far. In this work, using the complex methodology of Electron Paramagnetic Resonance (EPR) and dissolved spin probes, we investigate nanostructuring phenomena in a series of API-ILs: [Cnmim][Ibu], [Cnmim][Gly], and [Cnmim][Sal] with n = 2, 4, and 6, respectively. We reveal similar trends for API-ILs and common ILs, as well as peculiarities inherent to the studied API-ILs. Unusual behavior observed for [Cnmim][Ibu] has been assigned to the presence of a non-polar fragment in the [Ibu]- anion, which leads to the formation of more complex nanostructures around the radical compared to common ILs. Understanding general trends in the formation of such self-organized molecular structures is of fundamental interest and importance for applying API-ILs.

KW - EPR

KW - ionic liquids

KW - nanostructuring

KW - pharmaceuticals

KW - spin probes

UR - http://www.scopus.com/inward/record.url?scp=85136694153&partnerID=8YFLogxK

U2 - 10.3390/molecules27165117

DO - 10.3390/molecules27165117

M3 - Article

C2 - 36014356

AN - SCOPUS:85136694153

VL - 27

JO - Molecules

JF - Molecules

SN - 1420-3049

IS - 16

M1 - 5117

ER -