Spectrophotometric Determination of Mesalamine by Diazotization Coupling Reaction in Solid Dosage Forms

Two simple, sensitive spectrophotometric methods (Method A and B) are developed based on the diazotization of Mesalamine with nitrous acid (NaNo2/ HCl) at cold temperature followed by its coupling in-situ with Chromotropic acid (Method A) to yield cherry red coloured chromogen, phloroglucinol (Method B) to yield yellow coloured chromogen, exhibiting absorption maxima at 433nm and 421nm , respectively. Beer's law was obeyed in the concentration ranges of 5-25 and 8-40g/ml respectively. The coloured chromogen was stable for 4hrs. These methods were extended to pharmaceutical formulations and there was no interference from any common excepients which are usually present in tablet dosage formulations. The results of analysis have been validated statistically and by recovery studies.