title: Determination of etoposide serum concentrations in small pediatric samples by an improved method of reversed-phase high-performance liquid chromatography.
abstract: Several specific assays have been developed for the measurement of etoposide in biological fluids. As large samples are required for high sensitivity, these systems are not appropriate for a pediatric practice. In the present study, however, an improved method for the determination of serum levels of the anticancer drug etoposide was developed, using high-performance liquid chromatography with fixed-wavelength ultraviolet detection. Etoposide was extracted from serum using dichloromethane. The efficiency of extraction from serum was 85.7 +/- 7.7% for etoposide and 81.1 +/- 8.4% for diphenylhydantoin, the internal standard. The serum concentrations of etoposide were measured in 0.2-ml serum samples. The lower limit of detection was 50 ng/ml. Each measurement was completed within 5 min. The linear quantitation range for etoposide was 0.05-50 microg/ml. This assay presents an alternative method for routine measurement of serum levels of etoposide in the pediatric oncology setting.
authors.affiliation: Department of Pediatrics, National Hiroshima Hospital Higashi-Hiroshima 739-0041, Japan. Yasuhiro.Kato@mb7.seikyou.ne.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kato
authors.forename: Hideo
authors.initials: H
authors.lastname: Mawatari
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Nishimura
authors.forename: Nobuo
authors.initials: N
authors.lastname: Sakura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ueda
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000097:blood*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005047:Etoposide / Q000097:blood*; D006801:Humans; D012680:Sensitivity and Specificity
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005047:Etoposide