LC-PDA-ORD Bioassay of S-(+) and R-(-) Colchicine on Rat Dried Blood Spots: Application to a Pharmacokinetic Study

Abstract

A simple and sensitive normal phase liquid chromatographic method was developed and validated for quantification of Colchicine (COL) enantiomers on rat dried blood spots (DBS). The COL was extracted systematically from FTA spotted DBS cards using ethanol: methanol (85:15, v/v). Chromatographic separation was accomplished on Chiralcel OJ-H column using mobile phase composition of n-hexane:ethanol:diethylamine (75:25:0.1, v/v). The detection by PDA detector at 245 nm and elution order by polarimeter was monitored. The effect of hematocrit on extraction of COL enantiomers from DBS was studied. The average accuracy of enantiomers of COL were found to be 99.3% and 98.2%, respectively. The calibration curves were found to be linear over the concentration range of 1-500 μg/mL. The developed method was used to study the pharmacokinetics of COL enantiomers in rat blood samples.