Spectrophotometric Assay of Mesalazine in Pharmaceutical Preparations Via Oxidative coupling reaction with o-cresol and sodium metaperiodate

A simple, straightforward, rapid, sensitive and an accurate UV-VIS spectrophotometric method was suggested for the determination of mesalazine in bulk sample and in dosage forms. The method is relying on the oxidation of mesalazine by sodium metaperiodate followed by coupling with o-cresol in alkaline medium to form a blue indophenol dye which absorbs at 645 nm. Beer's law is obeyed in the concentration range 0.4- 12 g/ml of the drug with good accuracy (average recovery) 101.38% and precision (RSD) is less than 3.5%. The molar absorptivity is 22435 l.mol-1.cm-1 with detection limit 0.101 g/ml and 0.338 g/ml as quantification limit. The recommended method is effectively applied to the determination of mesalazine in pharmaceutical dosages (tablets and capsule). The analytical results were well-matched with the standard method British pharmacopeia) and validated good accuracy and precision.