Synthesis and characterization of new biodegradable polyurethanes containing azo derivatives of 5-aminosalicylic acid


Abstract The purpose of this study is to develop colon-specific drug delivery systems with pH-sensitive drug release properties.The azo polyurethane were characterized, and the drug content of the azo polyurethane was determined.Their behaviour and hydrolytic degradation was studied in simulated gastric fluid (SGF, pH =4) and simulated intestinal fluid (SIF, pH =7.8). All synthesized monomers and polymers were characterized by FTIR, 1H-NMR spectra.The release of 5-ASA under physiological conditions (pH = 7.8 and pH = 4) was investigated at body temperature (37 ºC). The release rate of 5-ASA increased with increasing pH (7.8 > 4).