A strategy for extending the applicability of a validated plasma calibration curve to quantitative measurements in multiple tissue homogenate samples: a case study from a rat tissue distribution study of JI-101, a triple kinase inhibitor.

A general practice in bioanalysis is that, whatever the biological matrix the analyte is being quantified in, the validation is performed in the same matrix as per regulatory guidelines. In this paper, we are presenting the applicability of a validated LC-MS/MS method in rat plasma for JI-101, to estimate the concentrations of JI-101 in various tissues that were harvested in a rat tissue distribution study. A simple protein precipitation technique was used to extract JI-101 and internal standard from the tissue homogenates. The recovery of JI-101 in all the matrices was found to be >70%. Chromatographic separation was achieved using a binary gradient using mobile phase A (acetonitrile) and B (0.2% formic acid in water) at a flow rate of 0.30 mL/min on a Prodigy ODS column with a total run time of 4.0 min. The MS/MS ion transitions monitored were 466.1 → 265 for JI-101 and 180.1 → 110.1 for internal standard. The linearity range was 5.02-4017 ng/mL. The JI-101 levels were quantifiable in the various tissue samples harvested in this study. Therefore, the use of a previously validated JI-101 assay in plasma circumvented the tedious process of method development/validation in various tissue matrices.

Highly sensitive method for the determination of a novel triple kinase inhibitor with anti-cancer activity, JI-101, in rat plasma by liquid chromatography-electrospray ionization tandem mass spectrometry: application to a pharmacokinetic study.

A highly sensitive, rapid assay method has been developed and validated for the estimation of JI-101 in rat plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive-ion mode. The assay procedure involves extraction of JI-101 and phenacetin (internal standard, IS) from rat plasma with a solid-phase extraction process. Chromatographic separation was achieved using a binary gradient using mobile phase A (acetonitrile) and B (0.2% formic acid in water) at a flow rate of 0.30 mL/min on a Prodigy ODS column with a total run time of 4.0 min. The MS/MS ion transitions monitored were 466.1 → 265 for JI-101 and 180.1 → 110.1 for IS. Method validation and sample analysis were performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 5.03 ng/mL and the linearity range extended from 5.03 to 2014 ng/mL. The intra-day and inter-day precisions were in the ranges of 1.17-19.6 and 3.09-10.4%, respectively. This method has been applied to a pharmacokinetic study of JI-101 in rats.