Development and Validation of a High-Performance Liquid Chromatography–Tandem Mass Spectrometry Method for the Simultaneous Determination of Irinotecan and Its Main Metabolites in Human Plasma and Its Application in a Clinical Pharmacokinetic Study

Abstract

Irinotecan is currently used in several cancer regimens mainly in colorectal cancer (CRC). This drug has a narrow therapeutic range and treatment can lead to side effects, mainly neutropenia and diarrhea, frequently requiring discontinuing or lowering the drug dose. A wide inter-individual variability in irinotecan pharmacokinetic parameters and pharmacodynamics has been reported and associated to patients’ genetic background. In particular, a polymorphism in the UGT1A1 gene (UGT1A1*28) has been linked to an impaired detoxification of SN-38 (irinotecan active metabolite) to SN-38 glucuronide (SN-38G) leading to increased toxicities. Therefore, therapeutic drug monitoring of irinotecan, SN-38 and SN-38G is recommended to personalize therapy. In order to quantify simultaneously irinotecan and its main metabolites in patients’ plasma, we developed and validated a new, sensitive and specific HPLC–MS/MS method applicable to all irinotecan dosages used in clinic. This method required a small plasma volume, addition of camptothecin as internal standard and simple protein precipitation. Chromatographic separation was done on a Gemini C18 column (3 μM, 100 mm x 2.0 mm) using 0.1% acetic acid/bidistilled water and 0.1% acetic acid/acetonitrile as mobile phases. The mass spectrometer worked with electrospray ionization in positive ion mode and selected reaction monitoring. The standard curves were linear (R2 ≥0.9962) over the concentration ranges (10–10000 ng/mL for irinotecan, 1–500 ng/mL for SN-38 and SN-38G and 1–5000 ng/mL for APC) and had good back-calculated accuracy and precision. The intra- and inter-day precision and accuracy, determined on three quality control levels for all the analytes, were always <12.3% and between 89.4% and 113.0%, respectively. Moreover, we evaluated this bioanalytical method by re-analysis of incurred samples as an additional measure of assay reproducibility. This method was successfully applied to a pharmacokinetic study in metastatic CRC patients enrolled in a genotype-guided phase Ib study of irinotecan administered in combination with 5-fluorouracil/leucovorin and bevacizumab.

Development and validation of an UPLC–MS/MS method for the quantification of irinotecan, SN-38 and SN-38 glucuronide in plasma, urine, feces, liver and kidney: Application to a pharmacokinetic study of irinotecan in rats

“…Recently, liquid chromatography coupled with mass spectrometry (LC-MS and LC-MS/MS) has become one of the preferred analytical tools for the rapid and efficient quantification of small and large molecules in different biological matrices due to the unique combination of high specificity, sensitivity and high sample throughput possibilities. Although several LC-MS/MS methods have been developed and implemented for the quantification of irinotecan and SN-38 in rabbit, mouse and human plasma, very few of them developed a UPLC-MS/MS method of SN-38 glucuronide [28–31]. Similarly, though quantification of irinotecan and SN-38 was done in mouse tissues (brain, liver, kidney etc.…”

Analytical Validation of Clopidogrel in Human Plasma Through Ultrahighperformance Liquid Chromatography-Tandem Mass Spectrometry

“…According to the experiment performed, the matrix factor value obtained for the QCL was 101.376%, meaning that at this concentration, there was ions enhancement, although not significantly, the value was near 100% [10][11][12][13]. The matrix factor value obtained in the high concentration was 85.053%, meaning that there was ions suppression [14,15].…”

Vitamin D Enhances the Efficacy of Irinotecan through miR-627–Mediated Inhibition of Intratumoral Drug Metabolism

“…Acetic acid (HOAc) was purchased from Sigma. 100 μL culture medium from the cells treated by irinotecan for 48 h was collected, and then mixed with 100 μL ACN and methanol (v/v 1:1) spiked with internal standard, e.g., camptothecin (31). The mixture was vortexed and set on ice for 5 minutes, and then centrifuged at 13,000 rpm for 10 minute.…”