Quantitative Determination of Clavulanic Acid in Human Plasma by Liquid Chromatography–Tandem Mass Spectrometry and its Application to Pharmacokinetics Study

Abstract

<br /><span style="font-size: 9pt; mso-bidi-font-family: 'Times New Roman';">A rapid, selective and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay has been proposed for the determination of Clavulanic acid (CA) in human plasma using Diclofenac sodium as internal standard (IS). The analyte and IS were extracted from human plasma via solid phase extraction and the chromatographic separation was achieved on Inertsil ODS-3, 50 x 4.6 mm, 5µ column under isocratic conditions. Detection of CA and IS was done by tandem mass spectrometry, operating in positive ionization and multiple reaction monitoring (MRM) acquisition mode. The protonated precursor to product ion transitions monitored for CA and IS were m/z 365.2→240.2 and 409.2→228.2, respectively. The method was fully validated as per the US FDA guidelines. The linear dynamic range of CA was 7.564 - 897.893 ng/mL. The intra-batch and inter-batch precision (%CV) was ≤ 14.1% while the mean extraction recovery was 84.48 % across quality control levels. It was successfully applied to a bioequivalence study of Cefdinir/CA (125 mg/62.5 mg) suspension formulation in 32 healthy Indian male subjects under fasting condition.</span>