Time- and pH-dependent colon-specific drug delivery for orally administered diclofenac sodium and 5-aminosalicylic acid

Table 1 Dissolution conditions of 5-ASA coated pellets

pH	λmax (nm)	Time (h)	Simulated GI region
1.2	302	2	Stomach
6.0	330	1	Duodenum
7.2	330	5	Lower small intestine and colon

Table 2 Pharmacokinetic parameters after oral administra-tion of DS coated formulation and reference enteric formula-tion in dogs at a dose of 100 mg/body (n = 6, mean ± SE)

Parameter	Test formulation	Reference formulation
Cmax (mg/L)	8.17 ± 1.35	10.05 ± 1.66
tmax (h)	7.40 ± 0.35	4.50 ± 0.20
Ke (L/h)	0.56 ± 0.06	0.44 ± 0.11
tlag (h)	5.80 ± 0.42	2.80 ± 0.21
AUC0-tn (mg·h/L)	17.21 ± 2.09	19.91 ± 2.83
F (%)	86.38 ± 10.51	—