MACROMOLECULAR PRODRUGS OF 5- AMINO SALICYLIC ACID, 1: AZO CONJUGATES

Polymeric prodrugs of 5-aminosalicylic acid, a drug used for the treatment of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease, were synthesized and characterized. The active drug 5-aminosalicylic acid was first coupled to a spacer group via an azo bond. All spacer-pharmacon systems prepared have a terminal primary amino function, which by nucleophilic reaction was coupled under mild conditions to poly(methyl vinyl ether-co-maleic anhydride) (5) and poly(1-vinyl-2-pyrrolidon-co-maleic anhydride) (6), without crosslinking. The polymeric prodrugs were characterized by UV and NMR. All polymer derivatives are insoluble in water at acidic pH-range, but dissolve slowly in neutral or slight alkaline medium.