Pharmacokinetics of four 5-FU preparations administered rectally to rats and rabbits

Table 1 Comparison of tissue concentrations in rats among the four 5-FU preparations (^-x ± s, n = 5)

Group	Concentration
	Plasma (mg/L)	Rectal wall (mg/g)	Mesenteric lymph nodes (mg/g)
HBS	27.10 ± 15.06c	71.97 ± 21.64b	75.92 ± 21.81b
LBS	16.60 ± 15.03	46.82 ± 20.84b	41.93 ± 17.22b
SE	14.39 ± 9.40	154.11 ± 46.54ab	41.29 ± 15.30b
CE	19.47 ± 8.71c	156.60 ± 42.31ab	46.45 ± 13.41b

^bP < 0.01 vs plasma level;

^aP < 0.05 SE group vs HBS group, CE group vs LBS group;

^cP > 0.05 HBS group vs LBS group, CE group vs SE group. HBS: hydrophil-based (polyethylene glycols) suppositories; LBS: Lipophil-based (semi-synthetic fatty glyceride) suppositories SE: Simple (o/w) emulsion; CE: Complex (w/o/w) emulsion.

Table 2 Main pharmacokinetic parameters in rabbits after rectal administration of four 5-FU preparations (^-x ± s, n = 3)

Group	T1/2 (h)	Vd (L)	AUC [(mg·g)/L]	Cmax (mg/L)	Tmax (h)
HBS	1.19 ± 0.52	2.25 ± 1.01	95.41 ± 45.21b	39.56 ± 19.02	0.84 ± 0.41
LBS	1.92 ± 0.80	16.90 ± 7.44	20.44 ± 9.82	8.56 ± 3.70	0.55 ± 0.29
SE	4.54 ± 1.75	22.98 ± 10.51	35.60 ± 15.03	9.95 ± 3.97	0.40 ± 0.17
CE	2.10 ± 0.98	3.00 ± 1.42	126.19 ± 73.35b	30.48 ± 15.24	0.99 ± 0.49

^bP < 0.01 HBS group vs LBS group, CE group vs SE group. HBS: hydrophil-based (polyethylene glycols) suppositories; LBS: Lipophil-based (semi-synthetic fatty glyceride) suppositories SE: Simple (o/w) emulsion; CE: Complex (w/o/w) emulsion.