Abstract
A sensitive, specific and reproducible liquid chromatography coupled to tandem mass
spectrometric method was developed and validated for the estimation of ciprofloxacin,
an extensively used second-generation quinolone antibiotics, in human plasma. A liquid-liquid
extraction of ciprofloxacin and the internal standard, ofloxacin, has been approached
from the biological matrix using chloroform. Chromatographic separation was achieved
in positive ion modes, isocratically on a 3.5 μm C18 analytical column (75 mm×4.6 mm,
i.d.) with 0.2% formic acid solution in water: methanol (10:90, v/v) as mobile phase,
at a flow rate of 0.5 mL.min−1. The MS/MS ion transitions were monitored as 332.0→231.3 for ciprofloxacin and 362.2→261.0
for IS. The method showed good linearity in the range of 0.01–5.00 μg.mL−1 (r
2
>0.99) with a good precision (3.37–12.60%) and accuracy (87.25–114%). At the same
time, ciprofloxacin was found to be stable during stability studies viz. bench-top,
auto-sampler, freeze-thaw cycle and long-term. The developed and validated method
was successfully applied to measure plasma ciprofloxacin concentrations in a single
dose bioequivalence study.
Key words
ciprofloxacin - LC-MS/MS - bioequivalence study - human plasma - method validation
