Spectrophotometric Determination of Mesalazine with Phloroglycinol in Pharmaceutical Preparation


A simple sperctrophotometric method for the determination of mesalazine in aqueous solution is achieved. The method is based on the reaction of mesalizine, with excess nitrite, in an acidic medium, to produce the corresponding diazonium salt. After the removal of residual nitrite with sulphamic acid, the diazonium salt was coupled with phlorogycinol reagent in basic medium to produce, an intense yellow-orange coloured water-soluble and stable azo dye which exhibits maximum absorption at 430 nm. Beer,s law is obeyed in the concentration range of 5-300 μg of mesalazine in a fina0.34l volume of 25 ml i.e., 0.2-12 ppm with a molar absorptivity of 3.02×104l.mol-1.cm-1,a relative error of –o.56 to 0.19% and a relative standard deviation of± 0.34 to ±0.91 % depending on the concentration level. The proposed method has been applied successfully to determine mesalazine in pharmaceutical preparation as capsules.