Ultra-Sensitive and Validated method for Trace Quantification of Carcinogenic Benzene in Cetirizine Dihydrochloride

Benzene (BENZ) is classified as a Class 1 residual solvent according to ICH Q3C guidelines due to its established classification as a Group 1 human carcinogen. During the chemical production of Cetirizine Dihydrochloride (CTZ) API, Cetirizine Dihydrochloride tablet (CTZT), Levocetirizine Dihydrochloride (LCTZ) API, and Levocetirizine Dihydrochloride tablet (LCTZT), BENZ can appear as a residual process impurity with carcinogenic risk; development of a highly sensitive quantification method is a critical requirement for pharmaceutical quality control. This study focused on developing and validating a method for detecting trace-level BENZ in CTZ and LCTZ drug substance and drug product. The method demonstrated exceptional sensitivity, with a least detectable concentration of 0.04 ppm and a quantifiable concentration of 0.12 ppm, significantly lower than the ICH-mandated safety limit of 2 ppm. Linearity and accuracy studies yielded an outstanding percentage of samples spiked BEN in the drug substance and drug product of CTZ and LCTZ and found within acceptance limit, approving the method's validity in presence of the drug atmosphere. Conventional headspace GC-FID/GC-MS are established techniques for benzene analysis; the proposed HPLC method offers a simpler, cost-effective, and validated method, making it well suited for routine quality control laboratories where GC facilities may not be readily available.