In vitro and in vivo study of a colon-targeting pH-sensitive hydrocortisone sodium succinate hydrogel

Abstract

The aim of this study was to prepare and characterize a novel pH-sensitive hydrocortisone sodium succinate loaded hydrogel (HSS-GEL) for specifically delivering HSS to the colon, and evaluate its targeting property. In this study, SEM was adopted to detect the internal microstructure of the prepared hydrogels at different pH values (pH 1.2 and pH 7.4). The swelling behavior and the in vitro release behavior under different pH conditions were employed to verify the pH-sensitivity of the HSS-GEL. Furthermore, pharmacokinetic studies, gastrointestinal drug residue analysis and the improvement of HSS side-effects were conducted to investigate the in vivo colon-targeting efficiency of the HSS-GEL. Finally, the therapeutic effects of the HSS-GEL on the experimental colitis were also studied. All results suggested that the HSS-GEL presented desirable colon-targeting property and effective therapy of ulcerative colitis (UC) with few side-effects. Therefore, the HSS-GEL might have great potential application in UC treatment.