(T1230-01-01) Mutagenic NDSRI of Citalopram - Critical Structural Evaluation of Carcinogenic Category and Development of a Highly Sensitive LC-MS/MS Method Development for Quantification

Purpose: The Carcinogenic Potency Categorization Approach (CPCA) was determined to be the most effective method for comprehending the potency classification of the NDSRI. The CPCA embodies a cautious methodology and is ready to adapt as fresh perspectives arise. Although it represents a notable progress in evaluating the risk of NI’s, it is crucial to thoroughly examine different pertinent aspects of this predictive approach in order to pinpoint potential areas that could be enhanced. The USFDA has established five categories for NDSRI’s based on their potential limits and has also defined AI limits for each category of impurity . If a potential risk of NDSRI’s is detected in a pharmaceutical product, it is necessary to perform confirmatory testing on batches using highly sensitive and properly validated methods . A N-Nitroso Desmethyl Citalopram (N-NDCTM) is included in the FDA table as per the guidelines for Recommended Acceptable Intake Limits for Nitrosamine Drug Substance Related Impurities, and no literature says the root cause for the listed impurity So, it is mandated to have a quantification method in place for quantification of impurity. Extensive literature exists solely on the quantification of active compounds and other impurities, but no prior research has been undertaken on the NDSRI's of CTM in any domain, including pharmacopeia or publications. This study is a distinctive undertaking the development of quantification method for in-house developed tablets formulations .

Methods: This study primarily concentrates on the development of an HPLC method that is amenable to conversion into an LC-MS/MS method. The final LC-MS/MS technique is then thoroughly evaluated. The specifications on the model, manufacturer, and place of origin for all instruments are as follows: (a) HPLC is coupled with a PDA (photodiode array detector) -2680/Waters corporation/United States of America; (b) Sonicator – SONOREX/Bandelin/Germany; (c) pH meter - S400/Metter Toledo/Switzerland; (d) Micro Balance - XPR 2U/Mettler Toledo/ Switzerland; (e) Analytical Balance - MX 105/Mettler Toledo/ Switzerland; (f) LC-MS/MS – X500R QTOF/Sciex/Canada. The column is used as a Poroshell SB-C18 column manufactured by Agilent Technologies. The HPLC was operated with Empower-3 software from Waters Corporation, USA, and the LC-MS/MS was operated with SCIEX OS software from Sciex, Canada.

Results: The developed and validated method was found to have the required sensitivity, selectivity, linearity, and accuracy. The method specificity was confirmed by the lack of peaks near the retention periods of NDSRI. The method linearity and accuracy were validated within the range from the LOQ to 150% of the specified concentration. The sensitivity and selectivity of the LC-MS/MS method are extremely trustworthy. Therefore, it can be deduced that the new technique is straightforward, rapid, reliable, and robust, rendering it appropriate for adoption in any analytical laboratory.

Conclusion: The structural evaluation of CTM revealed that one of the primary degradation impurities could develop into an N-nitroso compound. Desmethyl citalopram, a major impurity of CTM, contains a secondary amine in its structure that triggers the formation of an NDSRI of CTM, known as N-Nitroso Desmethyl Citalopram. The CPCA assessment revealed that impurity possesses elevated carcinogenic or mutagenic characteristics, as impurity falls into category 1. The evaluation sets the impurity threshold at 26.5 ng per day. The method that was used to assess the estimation of N-Nitroso Drug Substrate-Related Impurities in Citalopram Pharmaceutical drug product has been validated for all relevant parameters.

References: 1. Pollock, B. G.; Citalopram: A Comprehensive Review. Expert Opinion on Pharmacotherapy, 2001, 2 (4), 681–698.
2. Wade, A. G.; Lepola, U.; Koponen, H. J.; Pedersen, V.; Pedersen, T. The Effect of Citalopram in Panic Disorder. British Journal of Psychiatry, 1997, 170 (6),549–553.Page 18 of 20

Acknowledgements: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Conflicts of Interest: The authors declare that they have no conflicts of interest.
Data Availability Statement:The data underpinning the findings of this study are contained inside the publication. If additional information is required, reach out to the corresponding author.