DPD functional tests in plasma, fresh saliva and dried saliva samples as predictors of 5-fluorouracil exposure and occurrence of drug-related severe toxicity

High‐throughput method to analyze tegafur and 5‐fluorouracil in human tears and plasma using hydrophilic interaction liquid chromatography/tandem mass spectrometry

“…The levels of these compounds in the samples are summarized in Table . The observed concentrations were within the normal therapeutic levels …”

“…Several reversed‐phase HPLC methods have been described for the separation and analysis of FT and 5‐FU . However, fluoropyrimidines, such as FT and 5‐FU, showed very weak retention in the reversed phase because of their structures.…”

“…For plasma samples, the simplest method available for preparation was the protein precipitation approach. The extraction methods used in the previous studies for FT and 5‐FU employed large volumes of plasma and solvent (0.1–2 mL) and complex sample pretreatment procedures involving LLE or SPE …”

“…This method requires only 10 μL of tear volume and 20 μL of human plasma because of its very high sensitivity. Therapeutic plasma levels of FT and 5‐FU have been reported to be 10–4000 and 1–400 ng/mL, respectively . Therefore, this method exhibits the high throughput and sensitivity required for routine screening and quantification in a clinical laboratory setting.…”

“…Several methods have been reported for determining the levels of FT and 5-FU in various matrices using gas chromatography mass spectrometry (MS) [14][15][16] and high-performance liquid chromatography (HPLC) with ultraviolet detection 17,18 or HPLC/tandem MS (MS/ MS). [19][20][21][22][23][24][25] To eliminate sample impurities in human body fluids, most of these analytical techniques employ extraction methods, such as liquid-liquid extraction (LLE) [14][15][16][17][18][19][20][21][23][24][25][26][27][28] and solid-phase extraction (SPE). 22 Furthermore, complex derivatives should be used for these methods.…”