Application of 19 F time-domain NMR to measure content in fluorine-containing drug products

It is necessary to show that the active content in the dosage form of drugs is within a certain narrow range of the label claim. In case of fluorinated drugs, the active content can be measured by high field solid state NMR because the excipients lack fluorine. To make NMR reachable to any laboratory, simple to use, and at a low cost, measurement of 19 F nucleus using a 23 MHz (for 1 H) low field benchtop time‐domain (TD) NMR was investigated. Three fluorinated drug products, cinacalcet, lansoprazole, and ciprofloxacin, were chosen for this study. The doses for these drug products range from 15 to 500 mg. The average drug content measured using 19 F TD‐NMR compares well with the reported label claims for the three drugs tested. 19 F TD‐NMR is a simple and non‐destructive technique to measure drug content in tablets. In addition, the accessibility and simplicity of the technique makes it an excellent process analytical technology tool for development and manufacturing in the pharmaceutical industry. Copyright © 2015 John Wiley & Sons, Ltd.