Moving towards fast characterization of polymorphic drugs by solid-state NMR spectroscopy

Publication date: 30 January 2018 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 148 Author(s): Rosalynn Quiñones, Robbie J. Iuliucci, Grayce Behnke, Ryanne Brown, Deben Shoup, Taylor M. Riedel, Christine Plavchak, Brooke E. Lininger, Jonathan M. Spehar Solid-state nuclear magnetic resonance (SS-NMR) spectroscopy has become a common technique to study polymorphism in pharmaceutical solids at high-resolution. However, high-throughput application of high resolution SS-NMR spectroscopy is severely limited by the long 1H spin-lattice relaxation (T1) that is common to solid phase compounds. Here, we demonstrate the use of paramagnetic relaxation reagents such as chromium (III) acetylacetonate (Cr(acac)3) and nickel (II) acetylacetonate (Ni(acac)2) for fast data acquisition by significantly reducing the T1 value for carbamazepine Forms I, II, III, and dihydrate, cimetidine Forms A and B, nabumetone Form I, and acetaminophen Form I polymorphs. High resolution 13C cross-polarization and magic angle spinning were used to measure T1 values for each polymorph. In order to confirm the absence of polymorphic transitions during SS-NMR experiments, powder x-ray diffraction was implemented. The amount of chromium ions incorporated by the recrystallization process was quantified by using inductively coupled plasma optical emission spectroscopy. Our results suggest that the paramagnetic ions added to the polymorphs do not affect the polymorphic transformation or t...
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research