Pharmacokinetic Comparison of Isoalantolactone and Alantolactone in Rats after Administration Separately by Optimization of an UPLC-MS² Method

Table 3

Stability of samples under different storage conditions ().

Condition	Concentration (ng/mL)			RSD%
	Added	Measured		Isoalantolactone	Alantolactone
		Isoalantolactone	Alantolactone
Three freeze-thaw cycles	5	4.42	4.17	8.24	11.61
	50	44.37	42.87	5.40	6.78
	400	384.45	365.34	14.68	7.10
Freezing for 20 days (−80°C)	5	3.98	4.27	11.42	10.52
	50	38.34	44.20	3.77	6.43
	400	369.48	391.30	7.24	11.16
Room temperature (20°C), 4 h	5	4.72	4.10	9.42	8.50
	50	43.23	41.29	1.44	5.33
	400	373.84	367.14	14.10	13.77
Autosampler for 24 h (20°C)	5	4.67	4.75	8.11	7.96
	50	45.51	46.12	4.56	2.11
	400	376.10	370.43	9.76	5.08