NMR Approaches to Study Drug-Surfactant Interactions: Insights From NOE, Relaxometry and Diffusometry

Area of Science:

• Supramolecular chemistry and physical chemistry

Background:

• Characterizing drug interactions within surfactant assemblies at atomic resolution is challenging due to system dynamics and heterogeneity.
• Nuclear magnetic resonance (NMR) spectroscopy offers a powerful solution for studying these complex systems under native-like conditions.

Purpose of the Study:

• To review and summarize key solution-state NMR techniques for characterizing drug-surfactant interactions.
• To highlight the application of NMR in elucidating binding mechanisms, structural changes, and dynamics at the atomic level.

Main Methods:

• Nuclear Overhauser effect (NOE) for spatial proximity information.
• Spin-relaxometry for local dynamics and rotational correlation times.
• Translational self-diffusometry for global motion, bound fraction (p_b), and partition coefficient (K).

Main Results:

• NMR provides atomistic insights into drug-surfactant interactions, including binding modes and molecular dynamics.
• Techniques like NOE, relaxometry, and diffusometry quantify key parameters relevant to pharmaceutical and chromatographic applications.
• An integrated view of structure, dynamics, and transport is achievable, crucial for understanding physicochemical behavior.

Conclusions:

• Solution-state NMR techniques, supported by theoretical models, offer incisive characterization of drug-surfactant systems.
• These NMR approaches are essential for a comprehensive understanding of drug behavior in complex supramolecular environments.
• The review provides a valuable resource for researchers investigating drug delivery and formulation.