The assay and stability of chlorpropamide in solid dispersion with urea

Thin layer chromatography followed by reflectance densitometry has been used to evaluate the stability of chlorpropamide-urea during the fusion process. Urea was found to decompose to biuret and chlorpropamide to p-chlorobenzenesulphonamide: several other unidentified decomposition products were detected. The energy for decomposition of chlorpropamide was 57.1 kJmol-1 for melts containing 15 and 30% chlorpropamide. Decomposition followed apparent first order kinetics.