Budesonide-liposomes inclusion complex in thermosensitive gel alleviates DSS-induced ulcerative colitis in mice

Purpose A novel formulation for Ulcerative Colitis (UC) treatment by rectal administration with budesonide liposomes (Bud Lip) and thermosensitive gel (Gel) were developed for future clinical use. To evaluate the anti-inflammatory activity and colon mucosal protection of this novel formulation compared with other three in mice.Methods Bud Lip was prepared by reverse evaporation method, and then dispersed in solutions with PL407 and PL188 by cold method. Male mice were induced to UC by dextran sulfate sodium (DSS) and were treated for 14 days by rectal administration, as follows: Bud enema (a conventional suspension formulation); Bud Lip; Bud Gel; Bud Lip-Gel; saline. And a negative control without colitis was also used. Disease activity index (DAI), macroscopic and microscopic damage score in colon tissues were used to evaluate the effect of therapy. The levels of IL-6 and IL-10 in serum, and the concentrations of TNF-α and IL-10 and myeloperoxidase (MPO) activity in colon tissue were also introduced.Results In UC mice model, Bud Lip-Gel showed inflammation was alleviated significantly, and the treatment was highly associated with lower DAI, less macroscopic and microscopic colonic damage and downregulation of pro-inflammatory cytokines TNF-α, IL-6 and MPO. Bud Lip-Gel had advantages over Bud, Bud Lip, Bud Gel in the treatment of active UC.Conclusion Novel Bud liposomes complex in thermosensitive Gel effectively mitigated symptoms, alleviated macroscopic and microscopic colon damage, and reduced inflammatory reaction in UC mice, which might be a potential strategy for UC treatment.