Detection Study Of Three Related Genotoxic Impurities In Benfotiamine

Benfotiamine is a fat-soluble derivative of vitamin B1,which improves the disadvantage of low bioavailability of water-soluble vitamin B1,increases the concentration of thiamine in blood and tissues,and thereby improves the therapeutic effect.This product had been marketed in many countries as a drug and dietary supplement.According to the requirements of ICH M7,the author conducted a comprehensive evaluation of the potential toxic structure in the production of this product and raw materials,and the results showed that three structures of Benzyl chloride,dichlorotoluene and benzotrichloride needed specific test study within the seven potential genetoxic structures which are impurities introduced by benzoyl chloride as a starting material in the synthesis of benfotiamine,and should be controlled with the separated limit of 136.7ppm,5.0ppm and 1.32 ppm.,Therefore,it is necessary to develop an impurity detection method and examine the method properties to detect their presence in the sample.After screening and optimization of experimental conditions,a method for the determination of residual benzyl chloride and dichlorotoluene in benfotiamine by headspace-gas chromatography was established.And validate the method with ICH requirement.The results of benzyl chloride indicate that: the concentration range is 25.1~167.0?g/ml,the linearly dependent coefficient(r)is 0.9992,the LOQ is 25.1?g/ml prepared with 30%limit,and LOD is 0.04?g/ml,the relative standard deviation(RSD)of precision is 3.7%,and the recovery ratio with spiked sample is 95.5%.The results of dichlorotoluene indicate that: the concentration range is 0.92~6.1?g/ml,the linearly dependent coefficient(r)is 0.9990,the LOQ is 0.92?g/ml,and LOD is 0.31?g/ml,the relative standard deviation(RSD)of precision is 5.2%,and the recovery ratio with spiked sample is 99.0%.The results prove the sensitivity can meet the requirement,the method is accuracy,stable and reliable which can test the residual benzyl chloride and dichlorotoluene in Benfotiamine effectively.After screening and optimization of experimental conditions,a method for the determination of residual benzotrichloride in benfotiamine by headspace-gas chromatography was established.The results of benzotrichloride indicate that: the LOD is 0.41?g/ml can reach the limit test requirement.And the solution stability,sensitivity,accuracy,repeatability,inter precision,specificity and robustness have been validated,all can reach the test requirement.The results prove the method is accuracy,stable and reliable which can test the residual benzotrichloride in Benfotiamine effectively.The GC-MS method proves the method has the good specificity.The three genetoxic impurities haven't been detectable in the many batches of Benfotiamine.