Simultaneous and Rapid Determination of Six Tyrosine Kinase Inhibitors in Patients with Non-Small Cell Lung Cancer Using HPLC-MS/MS

Table 6

Results of stability of six analytes (n = 3).

Analytes	Nominal concentration (ng/mL)	Freeze-thaw stability		12 h at room temperature		24 h in the autosampler		Long-term stability (1 month)
		Measured concentration (mean)	Accuracy (RE %)	Measured concentration (mean)	Accuracy (RE %)	Measured concentration (mean)	Accuracy (RE %)	Measured concentration (mean)	Accuracy (RE %)
Gefitinib	20	17.58	−12.10	17.46	−12.70	17.56	−12.20	17.47	−12.65
	100	88.85	−11.15	90.03	−9.97	86.11	13.89	88.34	−11.66
	500	543.30	8.66	553.20	10.64	556.10	11.22	541.33	8.27
Icotinib	100	91.87	−8.13	90.71	−9.29	91.04	−8.96	89.09	−10.91
	500	447.00	−10.60	446.90	−10.62	441.40	−11.72	433.56	−13.28
	2000	1920.00	−4.00	1972.00	−1.40	1969.00	−1.55	1950.43	−2.47
Erlotinib	100	87.75	−12.25	89.76	−10.24	87.53	−12.47	86.34	−13.66
	500	440.90	−11.82	450.70	−9.86	440.90	−11.82	430.55	−13.89
	2000	1887.00	−5.65	1950.01	−2.50	1938.00	−3.10	1840.11	−7.99
Crizotinib	20	18.05	−9.75	18.92	−5.40	18.94	−5.30	17.32	−13.40
	100	91.86	−8.14	93.22	−6.78	94.22	−5.78	93.21	−6.79
	500	541.90	8.38	550.80	10.16	550.70	10.14	544.13	8.83
Osimertinib	20	19.01	−4.95	17.80	−11.00	17.55	−12.50	19.02	−4.90
	100	88.06	−11.94	87.57	−12.43	85.95	−14.05	87.23	−12.77
	500	551.30	10.26	561.70	12.34	549.40	9.88	561.07	12.21
Afatinib	10	10.10	9.10	10.71	7.10	10.07	0.70	10.21	2.1
	50	53.57	7.14	53.56	7.12	51.78	3.56	49.03	−1.94
	200	219.92	9.96	219.97	9.85	218.24	9.12	209.23	4.627