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Context:Extensive or long-time use of corticosteroids often causes many toxic side-effects. The ion exchange resins and the coating material, Eudragit, can be used in combination to form a new oral delivery system to deliver corticosteroids. Objectives:The resin microcapsule (DRM) composed by Amberlite 717 and Eudragit S100 was used to target hydrocortisone (HC) to the colon in order to improve its treatment effect on ulcerative colitis (UC) and reduce its toxic side-effects. Methods:Hydrocortisone sodium succinate (HSS) was sequentially encapsulated in Amberlite 717 and Eudragit S100 to prepare the HSS-loaded resin microcapsule (HSS-DRM). The scanning electron microscopy (SEM) was employed to investigate the morphology and structure of HSS-DRM. Thein vitrorelease andin vivostudies of pharmacokinetics and intestinal drug residues in rat were used to study the colon-targeting of HSS-DRM. The mouse induced by 2,4,6-trinitrobenzenesulfonic acid was used to study the treatment of HSS-DRM on experimental colitis. Results:SEM study showed good morphology and structure of HSS-DRM. In thein vitrorelease study, > 80% of HSS was released in the colon environment (pH 7.4). Thein vivostudies showed good colon-targeting of HSS-DRM (Tmax = 0.97 h,Cmax = 118.28 µg/mL of HSS;Tmax = 2.16 h,Cmax = 64.47 µg/mL of HSS-DRM). Moreover, the HSS-DRM could reduce adverse reactions induced by HSS and had good therapeutic effects on the experimental colitis. Conclusions:The resin microcapsule system has good colon-targeting and can be used in the development of colon-targeting preparations. [ABSTRACT FROM AUTHOR]

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). Thein vitrorelease study andin vivostudy 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. [ABSTRACT FROM PUBLISHER]