Development and In Vivo Evaluation of Mesalazine Colon Targeted Tablets

The main objective of the present study was to develop colon-targeted tablets of mesalazine by wet granulation method using 33 Response surface method with design of experiment software and HPMC K4M, Eudragit RL100, Ethyl cellulose and PVP K-30 used 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 Mesalazine released from tablets at different time intervals was estimated by UV spectrophotometer. The formulation F26 released 98.16 % of mesalazine after 24 h, whereas marketed product drug release was 92.02 ± 2.15 after  24 h. From in vivo bioavailability studies, after oral administration of colon targeted tablet containing 400 mg mesalazine, the Cmax, Tmax, and AUC0–∞ of optimized formulation and marketed product was found to be 683.21 ± 0.03 ng/mL, 6.01 ± 0.04 h, 4150.12 ± 5.12 ng*h/mL and 445.34 ± 3.22 ng/mL, 4.00 ± 0.01 h, 3457.18 ± 5.32 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 tablet system is a promising vehicle for preventing rapid hydrolysis in gastric environment and improving oral bioavailability of mesalazine for the treatment of disease at colon region.