A Novel Reverse Phase HPLC Method for the Quantification of Potential Genotoxic Impurities in Doripenem Monohydrate: A Broad-Spectrum Carbapenem Antibiotic Drug

Abstract

A novel sensitive gradient reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the quantification of potential genotoxic impurities in doripenem monohydrate (DORIBAX) drug substance, namely mono-p-nitrobenzyl malonate, 1β-methyl bicyclic ketoester, desilylated β-keto ester, 1β-methyldiazoazetidinone, deprotected doripenem side chain, N-protected mercapto alcohol, protected doripenem and doripenem side chain. The analysis performed on Alliance Waters e2695 separation module on C18 (250 × 4.6) mm, 5 μm (make: Inertsil) column, oven temperature maintained at 40 ºC and UV detection at 270 nm. The separation was accomplished using buffer (pH 6.0 ± 0.05) and acetonitrile in the ratio of 98:2 v/v as mobile phase-A and acetonitrile as mobile phase-B, flow rate: 1.0 mL/min and injection volume: 50 μL. The proposed method was validated as per ICH guidelines in terms of limit of detection (LOD), limit of quantification (LOQ), linearity, precision, accuracy and specificity.