Table 34.

Pharmacokinetic parameter of rhein.

Administration route	Parameters	RE	REM	REE
i.g.	Tmax (h)	0.9 ± 0.1	6.7 ± 2.3*	10.7 ± 2.3**
Cmax (mg/L)	42.66 ± 14.41	0.058 ± 0.035**	0.95 ± 0.090**
t1/2ka (h)	0.2 ± 0.1	4.1 ± 1.6*	3.0 ± 0.5**
t1/2 α (h)	1.1 ± 0.8	5.7 ± 1.6*	1.5 ± 0.6
t1/2 β (h)	3.2 ± 0.6	6.0 ± 1.7**	6.4 ± 1.0**
CL/F (L/h/kg)	0.78 ± 0.28	97.65 ± 66.61**	5.21 ± 0.51*
i.v.	AUC0-∞ (h·mg/L)	80.28 ± 13.59	1.03 ± 0.76**	12.79 ± 0.96*
t1/2α (h)	0.1 ± 0.04	0.6 ± 0.4*	0.2 ± 0.1
t1/2β (h)	0.4 ± 0.1	3.8 ± 0.8**	2.9 ± 1.6*
CL/F (L/h/kg)	0.36 ± 0.11	0.93 ± 0.54	1.95 ± 0.68*
AUC0-∞ (h·mg/L)	2.40 ± 1.15	0.84 ± 0.40*	0.36 ± 0.092*
F abs (%)	33.5	15.2	2.9

*P < 0.05, **P < 0.01 versus RE group.

AUC = area under the concentration-time curve; C_max = peak plasma concentration; i.g. = intragastric administration; i.v. = intravenous; RE = rhein; REE = rhein ethylate; REM = rhein methylate; T_max = time of peak plasma concentration.