Analysis Of Genotoxic Impurities In Sitagliptin Phosphate

Drug safety has become an important part of the well-being of the people.It is not only closely related to the rationality of the drug itself,but also closely related to the impurities generated in the synthesis,production,storage and transportation of drugs.Among them,genotoxic impurities are the most attractive,which can damage DNA to cause gene mutation,chromosome rupture or recombination,threatening human medication safety and health due to their multiple source pathways,wide range,low concentration but high toxicity.With the increasingly stringent requirements on drug quality and drug safety,the regulatory concept of genotoxic impurities has been continuously updated and improved.The analysis and research of genotoxic impurities have occupied a very important position in the drug development process and played a decisive role in the speed of new drug marketing.Nowadays,our country has the largest number of diabete patients,and the majority of them are patients with type II diabetes.Therefore,it is urgent to control the blood glucose level of patients.Sitagliptin phosphate,whether used alone or in combination,has good clinical effects on type II diabetes with less side effects.The safety of sitagliptin phosphate is related to the health of many diabetic patients,so the impurity level in the drug should be strictly controlled.In this thesis,we analyzed and studied the possible genotoxic impurities in sitagliptin phosphate bulk drug,controlled within reasonable limits according to regulations,developed an appropriate analysis method,and detected the content of impurities in sitagliptin phosphate drug substance to ensure that the impurity content is within the specified limits.In the first part of the thesis,ethylenediamine,a potential genotoxic impurity in sitagliptin phosphate,was analyzed by high performance liquid chromatography-mass spectrometry(HPLC-MS).Ethylenediamine has been derivatized with p-toluenesulfonyl chloride to increase the color group,enhance the ultraviolet absorption and improve the sensitivity.Through optimizing the conditions of ion source,ion selection and flow equivalence,a suitable analytical method was developed.The results showed that ethylenediamine peak appeared in about 8.2 min.Blank reagent and sample had no interference to the detection of ethylenediamine.The quantitation limit was 1.66 ng/m L and the detection limit was 0.50 ng/m L.The overall average recovery of the test article at the low,medium,and high concentrations in the accuracy test was 102.4%,with RSD of 1.3%.The test results all proved that this method could effectively detect the content of ethylenediamine in sitagliptin phosphate drug substance with high sensitivity,short analysis time,low detection limit and accurate and reliable result.In the second part of the thesis,the genotoxic impurities of methyl chloroacetate and ethyl chloroacetate in sitagliptin phosphate were analyzed by gas chromatography-tandem mass spectrometry(GC-MS).The ion selection,injection method,solvent and sample treatment were optimized,an efficient and convenient analytical method was developed and validated.The results showed that the retention times of methyl chloroacetate and ethyl chloroacetate were4.480 min and 4.790 min,respectively,demonstrating a good resolution without interference from other substances.The LOQ and LOD for methyl chloroacetate were 1.45 ppm and 0.43 ppm,the LOQ and LOD for ethyl chloroacetate were 2.39 ppm and 0.72 ppm.The overall average recoveries of methyl chloroacetate and ethyl chloroacetate in the accuracy test were104.5% and 103.3%,with RSD of 1.9% and 2.4%.In addition,the method was simple to operate,with strong specificity and high sensitivity,thus meeting the requirements of the detection limit.In the third part of the thesis,methyl chloride,a genotoxic impurity in sitagliptin phosphate drug substance,was analyzed by gas chromatography,and the conditions of chromatographic column and flow rate were optimized,respectively.Methyl chloride peaks within about 7.72 min.The average recovery in the accuracy test was 92.0%,and RSD was1.1%.The experimental results have proved that this method can effectively detect the content of chloromethane in sitagliptin phosphate.In addition,the method has the advantages of simple operation,strong specificity,good resolution and high accuracy.There are 45 figures,55 tables and 103 references in this thesis.