Pharmacokinetic parameters.

The aim of the study was to develop colon targeted tablets of Sulfasalazine (SSZ) by wet granulation method using 33 Response surface method with design of experiment software and Eudragit RS 100, Eudragit RL 100-55, Ethyl cellulose and PVP K-30 as pH dependent polymers. All the formulations (F1 to F27) were evaluated for the physicochemical parameters and were subjected to in vitro drug release studies. The amount of Sulfasalazine released from tablets at different time intervals was estimated by UV spectrophotometer. The formulation F17 shown 98.21±1.15 of Sulfasalazine after 24 h, whereas marketed product drug release was 96.21±1.87 after 1 h. The results of the study showed that formulation F17 is the best formulation on the basis of drug release and other evaluation parameters. From in vivo bioavailability studies, after oral administration of colon targeted tablet containing 500 mg Sulfasalazine, the Cmax, Tmax, and AUC0–∞ of optimized formulation and marketed product was found to be 684.31±4.03 ng/mL, 6.01±0.04 h, 4525.12±2.02 ng*h/ mL and 702.26±3.23 ng/mL, 1.50±0.01h, 3335.18±2.02 ng*h/mL respectively. Cmax, Tmax and AUC values of optimized formulation were found to be significantly higher than of marketed product. The pH dependent system is a promising vehicle for preventing rapid hydrolysis in gastric environment and improving oral bioavailability of Sulfasalazine in the effective management of colon related diseases.