High-Resolution Solid-State NMR Spectroscopy: Characterization of Polymorphism in Cimetidine, a Pharmaceutical Compound

Abstract

High-resolution solid-state NMR (SSNMR) spectroscopy has many advantages as a tool to characterize solid-phase material that finds applications in polymer chemistry, nanotechnology, materials science, biomolecular structure determination, and others, including the pharmaceutical industry. The technology associated with achieving high resolution has evolved to where SSNMR spectroscopy has become routine. To highlight SSNMR spectroscopy capability, an experiment exploring polymorphism in a pharmaceutical compound is described. Polymorphism can be studied by one-dimensional 13C NMR spectroscopy, presenting a straightforward experiment to highlight the techniques of cross-polarization, magic-angle spinning, and decoupling. To aid those unfamiliar with solid-state NMR methods, a detailed tutorial on the associated techniques is provided. The polymorphs of cimetidine, the active pharmaceutical agent of Tagamet, were selected to study. The development of the histamine H2-receptor antagonist was novel, and the ra...