Direct Comparison of 19F qNMR and 1H qNMR by Characterizing Atorvastatin Calcium Content

摘要

Quantitative nuclearmagnetic resonance (qNMR) is a powerful tool inmeasuring drug content because of its high speed, sensitivity, and precision. Most of the reports were based on proton qNMR (~1H qNMR) and only a few fluorine qNMR (~(19)F qNMR) were reported. No research has been conducted to directly compare the advantage and disadvantage between these two methods. In the present study, both ~(19)F and ~1H qNMR were performed to characterize the content of atorvastatin calcium with the same internal standard. Linearity, precision, and results from two methods were compared. Results showed that ~(19)F qNMR has similar precision and sensitivity to ~1H qNMR. Both methods generate similar results compared to mass balance method. Major advantage from 19F qNMR is that the analyte signal is with less or no interference from impurities. ~(19)F qNMR is an excellent approach to quantify fluorine-containing analytes.