title: A Simple High-Performance Liquid Chromatography for Determining Lapatinib and Erlotinib in Human Plasma.
abstract: Lapatinib and erlotinib are used for cancer treatment, showing large interindividual variability. Therapeutic drug monitoring may be useful for assessing the clinical outcomes and adverse events. A simple high-performance liquid chromatography UV method was developed for the determination of lapatinib and erlotinib in human plasma.
  
  
  
  An aliquot of plasma sample spiked with internal standard was treated with acetonitrile to precipitate the proteins. Lapatinib and erlotinib were separated on an octadecylsilyl silica gel column using a mobile phase consisting of acetonitrile, methanol, water, and trifluoroacetic acid (26:26:48:0.1) pumped at a flow rate of 1.0 mL/min. The detection wavelength was set at 316 nm.
  
  
  
  The calibration curves for lapatinib and erlotinib were linear (r = 0.9999) in the range of 0.125-8.00 mcg/mL. The extraction recoveries for both lapatinib and erlotinib at the plasma concentration of 0.125-8.00 mcg/mL were higher than 89.9% with coefficients of variation less than 3.5%. The coefficients of variation for intraday and interday assays of lapatinib and erlotinib were less than 5.1% and 6.1%, respectively.
  
  
  
  The present method can be used for blood concentration monitoring for lapatinib or erlotinib in exactly the same conditions.
authors.affiliation: *Department of Pharmaceutical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan; †Department of Pharmacy, Ibaraki Prefectural Central Hospital, Kasama, Japan; ‡Department of Pharmacy, University of Tsukuba Hospital, Tsukuba, Japan; §Department of Medical Oncology, Ibaraki Prefectural Central Hospital, Kasama, Japan; ¶Department of Respiratory Medicine, Ibaraki Prefectural Central Hospital, Kasama, Japan; and ‖Department of Breast and Endocrine Surgery, University of Tsukuba, Tsukuba, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ohgami
authors.forename: Masato
authors.initials: M
authors.lastname: Homma
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Kanako
authors.initials: K
authors.lastname: Naito
authors.forename: Motoko
authors.initials: M
authors.lastname: Yamada
authors.forename: Shoichi
authors.initials: S
authors.lastname: Mitsuhashi
authors.forename: Fumie
authors.initials: F
authors.lastname: Fujisawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kojima
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kaburagi
authors.forename: Keiko
authors.initials: K
authors.lastname: Uchiumi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yamada
authors.forename: Hiroko
authors.initials: H
authors.lastname: Bando
authors.forename: Hisato
authors.initials: H
authors.lastname: Hara
authors.forename: Keiji
authors.initials: K
authors.lastname: Takei
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D016903:Drug Monitoring / Q000379:methods; D000069347:Erlotinib Hydrochloride / Q000097:blood*; D006801:Humans; D000077341:Lapatinib; D010949:Plasma / Q000737:chemistry*; D011799:Quinazolines / Q000097:blood*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D000097:Acetonitriles; D011799:Quinazolines; D000077341:Lapatinib; D000069347:Erlotinib Hydrochloride; C032159:acetonitrile