@article{oai:stella.repo.nii.ac.jp:00000457,
 author = {Onishi, Hiraku and Matsuyama, Mototaka},
 issue = {9},
 journal = {Chemical and Pharmaceutical Bulletin},
 month = {},
 note = {application/pdf, A conjugate between prednisolone (PD) and chondroitin sulfate (CS) with glycine as a linker was prepared in order to obtain an effective macromolecular prodrug against inflammatory disease, especially rheumatoid arthritis. First, PD was converted to the N-trityl-glycine ester (Tr-GP), and the glycine ester of PD (GP) was obtained by detritylation of Tr-GP. Then, GP and CS were condensed with water-soluble carbodiimide to yield CS-GP. The obtained conjugate had a PD content of 2.24% (w/w). Conversion characteristics were investigated for GP and CS-GP to evaluate their potential as a prodrug. In the stability test of GP, PD was released well in the buffer at pH 6–7.4, but degraded rapidly at pH 8 without sufficient release of PD. As to CS-GP, PD was released more slowly than in GP, and the release rate rose with the increase in the medium pH. PD was released gradually from CS-GP over 24 h at a physiological pH. The conversion profiles of both GP and CS-GP almost followed pseudo-first order kinetics. The calculated conversion rate constants supported the gradual and effective release from CS-GP. The release rate of PD from GP and CS-GP was accelerated by the addition of rat plasma, but the promotion of release from CS-GP was small, suggesting that PD should be released gradually from CS-GP in the systemic circulation. It was demonstrated from the preliminary pharmacological study using rats with adjuvant-induced arthritis that CS-GP had high anti-inflammatory potential against arthritis.},
 pages = {902--912},
 title = {Conjugate between Chondroitin Sulfate and Prednisolone with a Glycine Linker: Preparation and in Vitro Conversion Analysis},
 volume = {61},
 year = {2013}
}