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A Sensitive Assay for Unbound Docetaxel Using Ultrafiltration plus HPLC-MS and Its Application to a Clinical Study

Authors :
David Wang
Natalie Hughes-Medlicott
Lilian Klingler
Yi Wang
Noelyn Hung
Stephen Duffull
Tak Hung
Paul Glue
Albert Qin
Rudolf Kwan
Wing-Kai Chan
Christopher Jackson
Source :
Pharmaceutics, Vol 16, Iss 5, p 602 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

Introduction: Docetaxel, a taxane used in the treatment of solid tumours, exerts pharmacological activity when in its unbound form. We report a sensitive assay to quantify unbound docetaxel after oral administration of docetaxel plus encequidar (oDox+E). Unbound drug quantification is important due to its direct correlation with drug-related toxicity and therapeutic efficacy. We improve on the sensitivity of current assay methods and demonstrate the utility of the assay on a novel formulation of oral docetaxel. Methods: Ultrafiltration followed by high-performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS) was utilized. Long-term stability, precision, accuracy, and recovery experiments were conducted to validate the assay. Additionally, patient samples from a Phase I dose-escalation pharmacokinetic study were analyzed using the developed assay. Results: The assay method exhibited long-term stability with an observed change between 0.8 and 6.9% after 131 days of storage at −60 °C. Precision and accuracy quality controls met the FDA acceptance criteria. An average recovery of 88% was obtained. Patient sample analysis demonstrated successful implementation of the assay. Conclusion: A validated sensitive assay was developed with an LLOQ of 0.084 ng/mL using 485 µL of human plasma. The sensitivity of the assay allowed quantification of unbound docetaxel concentrations in an early-phase oDox+E clinical study to compare it against IV docetaxel using pharmacokinetic modelling. Successful development of oDox+E represents an opportunity to replace the current IV docetaxel regimen with an oral regimen with lower cost, decreased side effects, and improve patient quality of life and experience.

Details

Language :
English
ISSN :
19994923
Volume :
16
Issue :
5
Database :
Directory of Open Access Journals
Journal :
Pharmaceutics
Publication Type :
Academic Journal
Accession number :
edsdoj.358746e1214a738575fdd1bdff5015
Document Type :
article
Full Text :
https://doi.org/10.3390/pharmaceutics16050602