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Application of a highly specific and sensitive fluorescent HPLC method for topotecan lactone in whole blood
Author(s) -
Hubbard K. Elaine,
Schaiquevich Paula,
Bai Feng,
Fraga Charles H.,
Miller Laura,
Panetta John C.,
Stewart Clinton F.
Publication year - 2009
Publication title -
biomedical chromatography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 65
eISSN - 1099-0801
pISSN - 0269-3879
DOI - 10.1002/bmc.1173
Subject(s) - topotecan , chromatography , chemistry , analyte , dosing , high performance liquid chromatography , excitation wavelength , whole blood , detection limit , protein precipitation , linear range , fluorescence , pharmacology , surgery , medicine , chemotherapy , physics , organic chemistry , quantum mechanics
Individualization of topotecan dosing reduces inter‐patient variability in topotecan exposure, presumably reducing toxicity and increasing efficacy. However, logistical limitations (e.g. requirement for plasma, intensive bedside plasma processing) have prevented widespread application of this approach to dosing topotecan. Thus, the objectives of the present study were to develop and validate an HPLC with fluorescence detection method to measure topotecan lactone in whole blood samples and to evaluate its application to individualizing topotecan dosing. Plasma samples (200 µL) were prepared using methanolic precipitation, a filtration step and then injection of 100 µL of the methanolic extract onto a Novapak® C 18 , 4 µm, 3.9 × 150 mm column with an isocratic mobile phase. Analytes were detected with a Shimadzu Fluorescence RF‐10AXL detector with an excitation and emission wavelength of 370 and 520 nm, respectively. This method had a lower limit of quantification of 1 ng/mL (S/N ≥ 5; RSD 4.9%) and was validated over a linear range of 1–100 ng/mL. Results from a 5‐day validation study demonstrated good within‐day and between‐day precision and accuracy. Data are presented to demonstrate that the present method can be used with whole blood samples to individualize topotecan dosing in children with cancer. Copyright © 2009 John Wiley & Sons, Ltd.