Comparison and Determination of the Content of Mosapride Citrate by Different qNMR Methods

As a salt-type compound, mosapride citrate's metabolism and side effects are correlated with its salt-forming ratio. Several techniques were developed in this work to compare various quantitative nuclear magnetic resonance (qNMR) methodologies and to quantitatively examine the content of raw materials. Among the qNMR techniques, methods for ¹H NMR and ¹⁹F NMR were developed. Appropriate solvents were chosen, and temperature, number of scans, acquisition time, and relaxation delay parameter settings were optimized. Maleic acid was chosen as the internal standard in ¹H NMR, and the respective characteristic signals of mosapride and citrate were selected as quantitative peaks. The internal standard in ¹⁹F NMR analysis was 4,4'-difluoro diphenylmethanone, and the distinctive signal peak at -116.15 ppm was utilized to quantify mosapride citrate. The precision, repeatability, linearity, stability, accuracy, and robustness of the qNMR methods were all validated according to the ICH guidelines. By contrasting the outcomes with those from high-performance liquid chromatography (HPLC), the accuracy of qNMR was assessed. As a result, we created a quicker and easier qNMR approach to measure the amount of mosapride citrate and evaluated several qNMR techniques to establish a foundation for choosing quantitative peaks for the qNMR method. Concurrently, it is anticipated that various selections of distinct quantitative objects will yield the mosapride citrate salt-forming ratio.