Colon-specific delivery of R68070, a new thromboxane synthase inhibitor, using chitosan capsules: therapeutic effects against 2,4,6-trinitrobenzene sulfonic acid-induced ulcerative colitis in rats

The objective of this study was to estimate the therapeutic effects of R68070, a new thromboxane synthase inhibitor, on 2,4,6-trinitrobenzenesulfonic acid sodium salt (TNBS)-induced ulcerative colitis in rats. We also examined the acceleration of the healing effect of R68070 with chitosan capsules to achieve its colon-specific delivery. The colonic injury and inflammation were assessed by measuring the myeloperoxidase (MPO) activities, colon wet weight/body weight (C/B) ratio and the damage score, respectively. These markers were decreased by the oral administration of R68070 with chitosan capsules and carboxymethyl-cellulose (CMC) suspension. The therapeutic effects of R68070 against ulcerative colitis were observed in both dosage forms in a dose dependent manner. In addition, its therapeutic effects were increased by the use of chitosan capsules, compared with CMC suspension. These results suggest that chitosan capsule might be a very useful dosage form for the colon-specific delivery of R68070 as an anti-inflammatory drug and for the therapy of ulcerative colitis.