The monographs published in the United States Pharmacopoeia – National Formulary (USP-NF) contain some of the most trusted and widely used assays across the pharmaceutical industry. Detailing the analysis of a wide range of products, such as active pharmaceutical ingredients (APIs), excipients, and other small molecules, these methods make use of a variety of instrumentation, such as high-performance liquid chromatography (HPLC), infrared (IR) spectroscopy, UV-vis spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy.
While relatively few assays in the USP-NF make use of NMR, the inherently quantitative nature of this technique makes it a very powerful tool for quantitative analyses (qNMR). However, most of the assays published in these monographs require the use of high-field NMR spectrometers (≥300 MHz). Due to the large upfront and recurring costs of these instruments, in addition to their space requirements, these powerful systems are often too expensive to purchase and maintain for most laboratories. The enhanced sensitivity and peak dispersion inherent to larger magnetic fields, while often beneficial and sometimes necessary for more complex research applications involving structural elucidation, are not always required when NMR is used as a technique for routine testing.
The emerging popularity of benchtop NMR instruments has addressed many of the accessibility concerns associated with traditional high-field instruments. These systems make use of permanent magnet technology, enabling them to operate without the use of cryogens. Additionally, they do not require expert staff for maintenance and non-experts can use them to collect high quality data. These factors, combined with their small size and portability, uniquely positions these instruments for quality control (QC) assays, like those highlighted in the USP-NF monographs. Indeed, the accessibility, affordability, and automatability of benchtop NMR instruments means that these are uniquely suited for use by non-experts in these QC settings. In this presentation, we will discuss our recent work demonstrating that benchtop NMR technology can be used to perform several assays contained within the USP-NF.