Investigation of the colon-targeting, improvement on the side-effects and therapy on the experimental colitis in mouse of a resin microcapsule loading dexamethasone sodium phosphate

Abstract

Context: Dexamethasone is the major drug in the treatment of ulcerative colitis (UC). However, the extensive or long-time use of dexamethasone causes many toxic side-effects. Ion exchange resins react with external-ions through their own functional groups and Eudragit S occurs degradation when pH > 7. These features make them suitable for oral delivery system.

Objective: Resin microcapsule (DRM) composed by 717 anion exchange resin and Eudragit S100 was used to target dexamethasone to the colon to improve its treatment effect on UC and reduce its toxic side-effects.

Results: Dexamethasone sodium phosphate (DXSP) was sequentially encapsulated in 717 anion-exchange resin and Eudragit S100 to prepare the DXSP-loaded resin microcapsule (DXSP-DRM). The in vitro release study and in vivo study of pharmacokinetics and the intestinal drug residues in rat demonstrated the good colon-targeting of DXSP-DRM. Moreover, the DXSP-DRM can reduce the toxic side-effects induced by DXSP and have good therapeutic effects on colitis mouse induced by 2,4,6-trinitrobenzenesulfonic acid.

Discussion: Dexamethasone can be targeted to the colon by DRM, thereby enhancing its treatment effect and reducing its toxic side effects.

Conclusion: The resin microcapsule system has good colon-targeting and can be used in the development of colon-targeted preparations.

• Anion exchage resin
• colon-targeting
• dexamethasone sodium phosphate
• side-effects
• ulcerative colitis

Declaration of interest

This work was financially supported by Fundamental Research Funds for the Central Universities (xj08142016 and xjj2013054), China Postdoctoral Science Foundation Funded Project (2014M562429) and Natural Science Foundation of China (No. 30973578 and No. 81473177). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Ethical approval

The study protocol was approved by the Xi’an Jiaotong University Medical and Biological Research Ethics Committee.