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Updated: Jun 9, 2026

Application and Methodology of the Non-destructive 19F Time-domain NMR Technique to Measure the Content in Fluorine-containing Drug Products
Published on: August 22, 2017
Solid-state carbon NMR characterization and investigation of intrinsic dissolution behavior of fluconazole
Hee Jun Park1, Min-Soo Kim, Jeong-Soo Kim
1Center for Nanotechnology-Based New Drug Dosage Form, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon 305-764, Republic of Korea.
Abstract:
Solid-state (13)C nuclear magnetic resonance ((13)C-SSNMR) revealed significant differences in the chemical shift of specific carbon atoms between two fluconazole polymorphs, reflecting a change in molecular conformation. A single resonance signal without splitting was observed in the spectrum of anhydrate form II, while the spectrum of anhydrate form I showed signals with splitting, indicating the presence of two dissimilar molecular conformations in the unit cell of anhydrate form I. The Fourier transform infrared (FT-IR) and Raman spectra associated with the triazole group, the 2,4-difluorobenzyl group, and the propane backbone provided also evidence of structural differences between forms I and II accompanying with (13)C-SSNMR. (1)H T(1) relaxation times, measured using saturation recovery experiments, showed that the metastable anhydrate form II was more mobile than the stable form I. The solubility and intrinsic dissolution tests showed that the anhydrate form II was more soluble and dissolved faster than the anhydrate form I.
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