Stability of 5-FU in whole blood and a clinical sampling and delivery procedures for TDM
- VernacularTitle:5-FU在全血中的稳定性及其TDM临床采样转运流程研究
- Author:
Yongqing WEN
1
;
Wenjuan WANG
1
;
Yu BAI
1
;
Rufeng LIU
1
;
Xu MA
1
Author Information
1. Dept. of Pharmacy，Peking University Cancer Hospital & Institute/Key Laboratory of Carcinogenesis and Translational Research （Ministry of Education），Beijing 100142，China
- Publication Type:Journal Article
- Keywords:
5-fluorouracil;
whole blood;
stability;
therapeutic drug monitoring;
clinical sampling and delivery procedures
- From:
China Pharmacy
2025;36(23):2963-2968
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE To investigate the stability of 5-fluorouracil （5-FU） in human blood and to establish a standardized clinical sampling and delivery procedure for therapeutic drug monitoring （TDM） of 5-FU. METHODS The EDTA-anticoagulated whole blood was used as the matrix to prepare stability assessment samples of 5-FU at both low （200 ng/mL） and high （5 000 ng/mL） concentrations （with groups without stabilizer and with 1% volume ratio of stabilizer）. The stability assessment samples were placed under room temperature （[ 25±2） ℃] and refrigerated （2-8 ℃） conditions， with sampling at 0， 0.5， 1， 2， 4， 7， and 24 h. After vortexing and centrifugation， the upper plasma layer was collected； proteins were precipitated using methanol， and the concentration of 5-FU in plasma was determined by liquid chromatography-tandem mass spectrometry. Based on the whole blood stability results， clinical sampling and delivery procedures were established. RESULTS The concentration of 5-FU in blank whole blood samples without stabilizers was significantly lower than that in samples with stabilizers （P＜0.05）. However， varying volumes （10， 25， 50 μL） of stabilizers had no significant effect on the measured concentrations of 5-FU in stability assessment samples with low and high concentrations （P＞0.05）. Without the addition of a stabilizer， low- and high-concentration 5-FU whole blood samples remained stable at room temperature for 0.5 h and 1 h， respectively， and under refrigeration for 2 h and 7 h， respectively. After the addition of a 1% stabilizer， the whole blood samples remained stable for up to 24 h under both room temperature and refrigerated conditions. Based on these findings， the following procedure was established： after collection， whole blood samples could be temporarily stored at room temperature （≤0.5 h） or at 4 ℃ （≤2 h）， and transported at 2-8 ℃. Upon delivery to the laboratory， a 1% volume ratio of stabilizer must be added immediately， followed by centrifugation within 24 h. The resulting plasma should be stored at －20 ℃ . CONCLUSIONS 5-FU in whole blood exhibits poor stability at room temperature. Refrigeration at 2-8 ℃ slightly improves stability ， but degradation still occurs rapidly. Adding a stabilizer at a 1% volume ratio significantly prolongs the refrigerated storage time. The established sampling and transport procedure for 5-FU TDM innovatively introduces the stabilizer addition step at the laboratory sample reception stage （rather than immediately after blood draw）. This approach ensures analytical quality while offering greater adaptability to real-world clinical sampling conditions， significantly improving practical feasibility.
