Probing the dynamics of complexed local anesthetics via neutron scattering spectroscopy and DFT calculations
Journal article, 2017

Since potential changes in the dynamics and mobility of drugs upon complexation for delivery may affect their ultimate efficacy, we have investigated the dynamics of two local anesthetic molecules, bupivacaine (BVC, C18H28N2O) and ropivacaine (RVC, C17H26N2O), in both their crystalline forms and complexed with water-soluble oligosaccharide 2-hydroxypropyl-?-cyclodextrin (HP-?-CD). The study was carried out by neutron scattering spectroscopy, along with thermal analysis, and density functional theory computation. Mean square displacements suggest that RVC may be less flexible in crystalline form than BVC, but both molecules exhibit very similar dynamics when confined in HP-?-CD. The use of vibrational analysis by density functional theory (DFT) made possible the identification of molecular modes that are most affected in both molecules by insertion into HP-?-CD, namely those of the piperidine rings and methyl groups. Nonetheless, the somewhat greater structure in the vibrational spectrum at room temperature of complexed RVC than that of BVC, suggests that the effects of complexation are more severe for the latter. This unique approach to the molecular level study of encapsulated drugs should lead to deeper understanding of their mobility and the respective release dynamics.

Inelastic neutron scattering

Local anesthetics






Murillo L. Martins

Niels Bohr Institute

Juergen Eckert

Los Alamos National Laboratory

University of South Florida

Henrik Jacobsen

University of Oxford

Niels Bohr Institute

Éverton C. dos Santos

Niels Bohr Institute

Norwegian University of Science and Technology (NTNU)

Rosanna Ignazzi

Niels Bohr Institute

Daniele Ribeiro de Araujo

Universidade Federal do ABC

Marie Claire Bellissent-Funel

University Paris-Saclay

Francesca Natali

National Research Council of Italy (CNR)

Institut Laue-Langevin

M. Koza

Institut Laue-Langevin

Aleksandar Matic

Chalmers, Physics, Condensed Matter Physics

Eneida de Paula

State University of Campinas

Heloisa N. Bordallo

Niels Bohr Institute

International Journal of Pharmaceutics

0378-5173 (ISSN)

Vol. 524 1-2 397-406

Driving Forces

Sustainable development

Areas of Advance

Building Futures (2010-2018)

Subject Categories

Condensed Matter Physics



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