Liquid chromatography‐tandem mass spectrometry method for simultaneous assessment of ofloxacin and dexamethasone in ocular biofluids: Application to ocular pharmacokinetic studies
Sachin Nashik Sanap, Amol Chhatrapati Bisen, Sristi Agrawal, Arpon Biswas, Anjali Mishra, Mukesh Kumar, Sarvesh Kumar Verma, Abhijit Deb Chaudhary, Rabi Sankar Bhatta
Abstract
Abstract A simple, fast, and responsive liquid chromatography‐tandem mass spectrometry method was established and fully validated according to the United States Food and Drug Administration guidelines for the simultaneous quantitation of ofloxacin and dexamethasone in tear fluid and partially in aqueous humor and cornea. Samples were cleaned‐ up by single‐step precipitation using methanol as an anti‐solvent. Agilent SB C 18 column with 4.5 min total run time was used for chromatographic separation utilizing isocratic mode. Mass spectrometry detection was carried out by a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring modes utilizing a positive electrospray ionization. The developed method showed a wide analytical range (ofloxacin: 0.7812–200 ng/ml and dexamethasone: 1.875–240 ng/ml) with good linearity ( r 2 > 0.99) and acceptable accuracy and precision. It also showed excellent recoveries (>85% for analytes) and a negligible matrix effect. Finally, this method was successfully applied to determine the pharmacokinetic profile of clinically used eye drop solution of ofloxacin and dexamethasone in preclinical rabbit tear fluid, suggesting its suitability for therapeutic drug monitoring in clinical practices.