Icotinib

The human NSCLC cell line HCC827, which was sensitive to icotinib and contained an EGFR exon 19 deletion (DelE746-A750), and the human normal pulmonary epithelial cell line BEAS-2B were purchased from Nanjing Cobioer Biological Science (Nanjing, China). The HCC827IR cell lines (HCC827IR1 and HCC827IR2) were generated by repeated exposure of HCC827 cells to gradually increased concentrations of icotinib (Dalian Meilun Biotechnology Co., Ltd., China) for over six months and HCC827IR-1 clones were selected for subsequent experiments and referred to as HCC827IR. The HCC827IR cells were cultured in RPMI-1640 medium (Gibco, USA) supplemented with 10% fetal bovine serum (Gibco, USA), penicillin (100 U/mL) and streptomycin (100 μg/mL). Pulmonary epithelial cell lines BEAS-2B were cultured in BEBM complete medium (Nanjing Cobioer Biological Science, China). All cell lines were maintained in a humidified incubator at 37 °C with 5% CO₂.

The analytes including gefitinib (lot: F1102AS), icotinib (lot: J0615A), afatinib (lot: M0320A), erlotinib (lot: J0615A), crizotinib (lot: A0320A), and carbamazepine (internal standard, IS) (lot: M1001AS) were supplied by Meilun Biotech Co., Ltd. (Dalian City, China). Osimertinib (lot: 1-NJL-79-1) was purchased from Toronto Research Chemicals (Toronto, Canada). Mass spectrometric reagents methanol and acetonitrile were obtained from Merck (Merck Company, Darmstadt, Germany).
Formic acid was purchased from Tedia Company Inc. (Tedia, Fairfield, OH, USA). Isopropanol reagent was purchased from Shanghai Titan Technology Co., Ltd. (Titan, Shanghai, China). Distilled water was purchased from Watsons Distilled Water Co., Ltd. (Watsons, Guangzhou, China). Human blank plasma was donated by healthy volunteers in our laboratory (Shanghai, China).