A novel ultra-performance liquid chromatography detection method development and validation for paclitaxel and its major metabolite in human plasma.

Background: Paclitaxel is a promising anticancer drug for patients with ovarian, breast, lung, gastrointestinal, genitourinary, prostate, and head-and-neck cancers. Paclitaxel follows nonlinear pharmacokinetics. The major metabolite of paclitaxel is 6-alpha-hydroxy paclitaxel, mediated by CYP2C8, while metabolism to two of its minor metabolites, 3'-p-hydroxypaclitaxel and 6a, 3'- p-dihydroxypaclitaxel, is catalyzed by CYP3A4. Therapeutic drug monitoring of paclitaxel could be a promising approach to improve the efficacy and safety of paclitaxel correct personalized doses and improve the overall benefit-risk ratio. A novel and highly sensitive chromatographic method for the detection of paclitaxel and its metabolite has been proposed that allows quantification in human plasma with 100% accuracy in terms of recovery without significant intraday or interday variations.

Materials And Methods: The present study was planned following bioanalytical method validation guidance according to the U.S. Food and Drug Administration requirements. The validation of the analytical procedure was performed as per ICH Q2(R1) guidelines. It was done to assure the reliability of the results obtained for various parameters such as linearity, accuracy, precision, limit of detection (LOD), limit of quantification, robustness, stability, and system suitability.

Results: The specificity of the method was established by ensuring no interference with peak obtained from paclitaxel and 6-alpha-hydroxy paclitaxel. LOD was found to be 0.05 and 0.033 while the limit of quantitation was 0.14 and 0.099 for paclitaxel and 6-alpha-hydroxy paclitaxel, respectively. Median (±interquartile range) accuracy for paclitaxel and 6-alpha-hydroxy paclitaxel was found to be 102.73 (±13.581) and 100.87 (±7.573), respectively.

Conclusion: This novel method of simultaneous detection of paclitaxel and its major metabolite 6-alpha-hydroxy paclitaxel demonstrated significant resolution and was sensitive enough for its quantification in human plasma.