TY - JOUR

T1 - Structural and sorption characteristics of an aerogel composite material loaded with flufenamic acid: insights from MAS NMR and high-pressure NOESY studies

AU - Sobornova, V.V.

AU - Mulloyarova, V.V.

AU - Belov, K.V.

AU - Dyshin, A.A.

AU - Tolstoy, P.M.

AU - Kiselev, M.G.

AU - Khodov, I.A.

N1 - Export Date: 4 November 2024 CODEN: PPCPF Сведения о финансировании: Russian Science Foundation, RSF, 22-13-00257 Сведения о финансировании: Russian Science Foundation, RSF Текст о финансировании 1: This research was funded by the grant of the Russian Science Foundation (project no. 22-13-00257).

PY - 2024/10/17

Y1 - 2024/10/17

N2 - The structural and sorption characteristics of a composite material consisting of a silica aerogel loaded with flufenamic acid were investigated using a variety of nuclear magnetic resonance techniques. The composite structure was analyzed using magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, which revealed significant interactions between the aerogel matrix and the FFA molecules. Solid-state 29Si NMR provided insights into the aerogel's stability, while 1H and 13C NMR confirmed the presence of FFA in the matrix, with signals from FFA molecules observed alongside tetraethoxysilane (TEOS) groups. Ethanol-induced desorption of FFA led to narrowed spectral lines, suggesting the breaking of intermolecular hydrogen bonds. 19F MAS NMR spectra indicated changes in FFA local environments upon loading into AG pores. Evaluation of CO2 sorption characteristics using 13C NMR demonstrated a slower sorption rate for AG + FFA than that for pure AG, attributed to decreased pore volume. Furthermore, nuclear Overhauser effect spectroscopy (NOESY) was employed to explore the conformational behavior of FFA within the aerogel matrix. The results indicated a shift in conformer populations, particularly those related to the rotation of one cyclic fragment relative to the other. These findings provide insights into the structural and sorption characteristics of the AG + FFA composite, which are valuable for developing novel drug solid forms. © 2024 The Royal Society of Chemistry.

AB - The structural and sorption characteristics of a composite material consisting of a silica aerogel loaded with flufenamic acid were investigated using a variety of nuclear magnetic resonance techniques. The composite structure was analyzed using magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, which revealed significant interactions between the aerogel matrix and the FFA molecules. Solid-state 29Si NMR provided insights into the aerogel's stability, while 1H and 13C NMR confirmed the presence of FFA in the matrix, with signals from FFA molecules observed alongside tetraethoxysilane (TEOS) groups. Ethanol-induced desorption of FFA led to narrowed spectral lines, suggesting the breaking of intermolecular hydrogen bonds. 19F MAS NMR spectra indicated changes in FFA local environments upon loading into AG pores. Evaluation of CO2 sorption characteristics using 13C NMR demonstrated a slower sorption rate for AG + FFA than that for pure AG, attributed to decreased pore volume. Furthermore, nuclear Overhauser effect spectroscopy (NOESY) was employed to explore the conformational behavior of FFA within the aerogel matrix. The results indicated a shift in conformer populations, particularly those related to the rotation of one cyclic fragment relative to the other. These findings provide insights into the structural and sorption characteristics of the AG + FFA composite, which are valuable for developing novel drug solid forms. © 2024 The Royal Society of Chemistry.

KW - Atomic emission spectroscopy

KW - Fourier transform infrared spectroscopy

KW - Hydrogen bonds

KW - Nuclear magnetic resonance spectroscopy

KW - Silicones

KW - Composites material

KW - Flufenamic acid

KW - High pressure

KW - Magic angle spinning nuclear magnetic resonance

KW - Material loaded

KW - matrix

KW - Nuclear overhauser effect spectroscopy

KW - Silica aerogels

KW - Sorption characteristics

KW - Structural characteristics

KW - Magic angle spinning

UR - https://www.mendeley.com/catalogue/5aa46590-e945-3c10-9ef7-2b40a46b93fb/

U2 - 10.1039/d4cp03217a

DO - 10.1039/d4cp03217a

M3 - статья

VL - 26

SP - 27301

EP - 27313

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

ER -