Table 4.

Stability data of 10 alkaloids in the beagle dog plasma. (n = 6).

Compound	Spiked Concentration (ng/mL)	Stability (% RE a)
		Short-Term	Long-Term	Three Freeze-Thaw	Post-Preparation
corydaline	1.1	3.86	4.90	−2.72	2.30
	34.8	−4.30	−4.52	−4.83	−4.36
	445.6	−1.88	−4.45	−3.63	−4.56
dehydrocorydaline	0.5	8.52	2.85	3.90	3.87
	16.1	4.15	5.16	10.41	13.40
	206.0	3.50	2.97	1.85	1.05
tetrahydropalmatine	1.0	−4.16	−4.47	−4.77	−4.36
	31.7	−1.92	−4.85	−4.76	2.09
	507.0	−2.69	−3.38	−3.36	−4.54
protopine	1.1	−4.47	−4.48	−6.91	−4.40
	33.8	−2.86	−4.78	−3.96	−3.63
	432.0	−4.96	−4.93	−4.38	−3.92
palmatine	1.0	−4.06	2.25	−2.08	−4.98
	32.8	−3.35	−4.59	−3.35	−3.35
	420.0	−3.83	−3.95	−2.02	−2.78
tetrahydroberberine	0.8	−2.54	−2.59	−4.69	−3.54
	26.3	−3.38	−4.95	−3.22	−4.74
	336.0	−3.32	−3.04	−3.92	−4.51
columbamine	0.8	−3.44	−3.46	−3.06	−1.75
	25.0	−2.54	−3.94	−4.49	−3.14
	320.0	−3.99	−4.88	−4.29	−4.42
berberine	1.1	−4.14	−4.51	−3.91	−3.47
	33.8	−1.87	−4.50	−4.62	−4.47
	432.0	−2.88	−4.28	−3.62	−4.08
coptisine	1.0	−5.42	−4.76	−3.90	−1.88
	31.3	−3.34	−4.31	−1.37	−4.31
	400.0	−4.14	−2.34	−2.09	−4.09
berberrubine	0.5	−12.10	−6.88	−7.75	−11.52
	14.4	10.68	−3.02	−13.61	−5.61
	184.0	1.39	−2.87	1.67	0.89

^a RE is expressed as (measured concentration/freshly prepared concentration⁻¹) × 100%.