Optimizing cancer patient care with a robust assay for 5-fluorouracil quantification and in-vitro stability in human blood for therapeutic drug monitoring.

ABSTRACT

Background: The plasma concentration of 5-Fluorouracil (5-FU) is affected by numerous factors, thereby limiting its efficacy. The current therapeutic regimen's doses based on body surface area (BSA) are linked to increased toxicity and sometimes inadequate drug exposure. Aim and objectives: The study aims to develop an in-vitro assay to monitor 5-Fluorouracil's therapeutic efficacy in cancer patients' blood samples, focusing on pharmacokinetics to improve therapy precision. Materials and methods: Drug levels were determined from standards, quality controls, and experimental samples using protein precipitation, liquid-liquid extraction, and separation using a C18 analytical column with an isocratic program. Result: In EXP-1A, the mean concentration of 5-Fluorouracil was 1.15 µg/ml; in EXP-1B, it was 1.16 µg/ml, while in EXP-1C, the mean concentration was 0.9 µg/ml. The percentage difference in mean 5-Fluorouracil concentration between the experiment sample containing a DPD inactivator and EXP-1C (without a DPD inactivator) was 21.5 % higher for EXP-1A and 0.68 % higher for EXP-1B. In the second phase of the experiment, the overall stability of 5-Fluorouracil in samples containing a DPD inactivator was 24.5 % superior compared to samples without a DPD inactivator. Conclusion: A modified extraction technique has been developed to accurately measure 5-Flourouracil concentration in blood, preserving its stability and concentration by adding a DPD inactivator.