Study On The Pharmaceutical Impurity Analysis With HPLC-QTOF-MS

Drug has done more and more significant contribution to human health, however drug impurities has many side effects.Traditional related substances analysis methods cannot meet our analysis need now, while technology such as HPLC-QTOF-MS,combining high efficient separation of HPLC with high sensitivity,high resolution of Q-TOF-MS has great advantage in qualitative and quantitative analysis and is better adapted to medicinalresearches on the demand for automation and high throughput. This technical has become one of the most powerful analysis methods of drug impurity structure researches in the frontier field.In this thesis, we identified the structure of the major impurities in cefradine API and anticancer drug hydrochloride gemcitabine, analyzed the plausible fragmentation pathways,speculated their possible source and provided a theoretical basis for improvement and supervision of drug production process.First, we established a suitable chromatographic condition for MS analysis, optimized proper MS conditions, identified the structure of impurities X by screening selected fragments. Impurity X was identified as4,5-dihydrophenylglycine.Impurities1,3in the group Y are para, ortho isomers of cefadroxil, impurities2,4,5in the group Y are the structure of cefradine hydroxylation, impurity6is with the structure of cefradine carbonylation. It was estimated that the by-product impurity X comes from the intermediate dihydrophenylglycine with little tetrahydrophenylglycine involved in the synthesis process. HPLC-QTOF-MS results confirm this estimation.Second,we identify the major impurity of gemcitabine hydrochloride for injection as2’-deoxy-2’,2’-difluorouridine and analyze the plausible fragmentation pathways.The high resolution datas errors are less than25ppm.NMR and UV comfirm our identification.We get a small amount of2’-deoxy-2’,2’-difluorouridine with purity99.8%by preparative LC.Its RRF is0.76and LOD is0.49μg-mL-1.We estimate2’-deoxy-2’,2’-difluorouridine results from following two factors.1.The synthetic process temperature is too high leading cytosine deamination to uracil.2.The sample in the process of recrystallization and circulation temperature is too high leading deamination.