Identification, trace level quantification, and in silico assessment of potential genotoxic impurity in Famotidine

Abstract

Potential genotoxic impurities in medications are an increasing concern in the pharmaceutical industry and regulatory bodies because of the risk of human carcinogenesis. To prevent the emergence of these impurities, it is crucial to carefully examine not only the final product but also the intermediates and key starting material (KSM) used in drug synthesis. During the related substances analysis of KSM of Famotidine, an unknown impurity in the range of 0.5–1.0% was found prompting the need for isolation and characterization due to the possibility of its to infiltrate into the final product. In this study, the impurity was isolated and characterized as 5-(2-chloroethyl)-3,3-dimethyl-3,4-dihydro-2H-1,2,4,6-thiatriazine 1,1-dioxide using multiple instrumental analysis, uncovering a structural alert that raises concern. Considering the potential impact of impurity on human health, an in silico genotoxicity assessment was established using Derek and Sarah tool in accordance with ICH M7 guideline. Furthermore, molecular docking and molecular dynamics simulation were performed to evaluate the specific interaction of the impurity with DNA. The findings reveal consistent interaction of the impurity with the dG-rich region of the DNA duplex and binding at the minor groove. Both in silico prediction and molecular dynamic study confirmed the genotoxic character of the impurity. The newly discovered impurity in famotidine has not been reported previously, and there is currently no analytical method available for its identification and control. A highly sensitive HPLC-UV method was developed and validated in accordance with ICH requirements, enabling quantification of the impurity at trace level in famotidine ensuring its safe release.

Keywords:

• Active pharmaceutical ingredients
• impurity profiling
• genotoxicity
• famotidine
• in silico prediction

Acknowledgement

B. R., F. S., V. N., and V. K. M. thank Amity University, Mumbai for all the support. Authors thanks IPCA Laboratories, Mumbai for the help to perform instrumental analysis of the samples.

Author contributions

B. R., F. S., and N. R. designed the study and interpreted the data. V. N. contributed to scientific discussion. V. K. M. conducted the molecular modeling and molecular dynamics simulations study. B. R. revised it critically, drafted and finally approved the version to be submitted.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data available within the article or its supplementary material. The datasets generated during and/or analyzed during the current study are available from the corresponding author on request.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.