Determination of Tofacitinib Citrate Tablets by Quantitative Proton Nuclear Magnetic Resonance

KeyWord:quantitative proton nuclear magnetic resonance£¨qHNMR£©  tofacitinib citrate tablets  3,5-dimethylpyrazole  content determination

Abstract:

      A quantitative proton nuclear magnetic resonance£¨qHNMR£© method was developed for determination on the effective content of tofacitinib citrate tablets£¬with dimethyl sulfoxide£¨DMSO£­D6£© as the solvent and 3£¬5-dimethylpyrazole as the internal standard£®Proton signal peaks of tofacitinib at ¦Ä 7.13 and ¦Ä 5.73 of 3£¬5-dimethylpyrazole were selected as the quantitative signals£¬respectively£®The spectra of the mixture complex were collected under the conditions of pulse sequence zg30£¬relaxation delay time£¨D1£© 26 s£¬and scanning number£¨NS£© 16 times at 298 K on Bruker Avance ¢ó 400 MHz NMR spectrometer£®qHNMR method with high specificity showed a good linear relationship in the concentration range of 0.793£­7.925 mg/mL£¬with linear correlation coefficient£¨r2£© up to 0.998 4£®The relative standard deviation£¨RSD£© of precision£¬repeatability and stability were 0.82%£¬1.7% and 0.67%£¬respectively£®The content of tofacitinib in tofacitinib citrate tablets was determined to be 2.25% by qHNMR£¬which was basically consistent with the results by high performance liquid chromatography£¨HPLC£©£®As a result£¬qHNMR method is an alternative way to determine the effective content of toacitinib cittrate tables£®More importantly£¬it has many outstanding advantages£¬such as simple operation£¬short detection time£¬no requirement for reference standards£¬simultaneously qualitative and quantitative analysis.