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Updated: Mar 25, 2026

Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring
Published on: December 9, 2010
Pulsed Field Gradient NMR with Sigmoid Shape Gradient Sampling To Produce More Detailed Diffusion Ordered
Guilhem Pagès1, Alice Bonny1, Véronique Gilard1
1Groupe de RMN Biomédicale, Laboratoire de Synthèse et Physicochimie de Molécules d'Intérêt Biologique UMR CNRS 5068, Université de Toulouse , 118 Route de Narbonne, 31062 Toulouse Cedex 9, France.
Abstract:
NMR diffusion measurements are based on signal attenuation. In the case of complex mixtures for which some molecules are diffusing quickly while others are significantly slower, it is challenging to obtain a diffusion ordered spectroscopy (DOSY)-type 2D map giving reliable information on all molecules. In this paper, we propose a new gradient sampling approach based on a sigmoid shape allowing the acquisition of a significant number of points for both the fast and slow diffusing molecules. We applied this new gradient sampling strategy to deformulate two medicines whose composition was known (Esomeprazole) or unknown (Mebendazole). PFG NMR associated with a sigmoid gradient ramp is an exciting strategy to study drugs as a whole, i.e., the active ingredient(s) and excipients.
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