An in vivo study on pharmacodynamics of 4-aminosalicylic acid oral colon-specific delivery coated tablets

AIM: To examine the pharmacodynamics of a self-developed oral colon-specific delivery coated tablets of 4-aminosalicylic acid (4-ASA) on rats. METHODS: Ulcerative colitis rat model was developed by intrarectal administration of 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) in alcohol. Rats were divided randomly into healthy control group, TNBS control group, TNBS+ lower dose (coated tablets) group, TNBS+ medium dose (coated tablets) group, TNBS+ higher dose (coated tablets) group, TNBS+ sulfasalazine (SASP) group. TNBS + medium dose non-coated tablet group. Several indices including macroscopic change, histological damage, and tissue myeloperoxidase (MPO) activity were examined after 5 consecutive oral drug administration to assess pharmacodynamics of the coated tablets. RESULTS: An experimental ulcerative colitis in rats was induced by TNBS. Compared with 4-ASA non-coated tablet group, decreased macroscopic and histological damage score and lower MPO activity were observed after the oral administration of 4-ASA coated tablets or SASP. There was no significant difference between the effects on the indices of higher dose of coated tablets and SASP (P＞0.05). CONCLUSION: The self-made 4-ASA oral colon-specific delivery coated tablet showes higher effect than non-coated tablets to treat ulcerative colitis in rats.