The Herb-Drug Pharmacokinetic Interaction of Fluoxetine and Its Metabolite Norfluoxetine with a Traditional Chinese Medicine in Rats by LC-MS/MS

Table 3

Stability of the analytes (n = 5).

	Concentration (ng/ml)	At room temperature for 4 h		Freeze-thaw three cycles		−20°C for 4 weeks
		Measured C (ng/ml)	RSD%	Measured C (ng/ml)	RSD%	Measured C (ng/ml)	RSD%
FLU	1	1.010 ± 0.028	2.77	0.997 ± 0.012	1.20	0.987 ± 0.018	1.82
	4	3.965 ± 0.210	5.30	3.991 ± 0.212	5.31	4.012 ± 0.231	5.76
	16	15.832 ± 0.536	3.39	15.872 ± 0.845	5.32	15.872 ± 0.654	4.12
NOF	2	1.943 ± 0.054	2.78	1.879 ± 0.045	2.39	1.873 ± 0.044	2.35
	4	3.934 ± 0.186	4.73	4.012 ± 0.231	5.76	3.891 ± 0.156	4.01
	8	7.897 ± 0.234	2.96	7.987 ± 0.341	4.27	7.871 ± 0.246	3.13

FLU: fluoxetine; NOF: norfluoxetine.