Original Articles: 2011 Vol: 3 Issue: 3
Different kinetic spectrophotometric methods for the determination of Mefenamic Acid, Niflumic Acid, Mesalazine and Sulfasalazine in their pharmaceutical formulation
The objective of this research was to develop simple and sensitive three kinetic methods for the determination of some anti-iflamatory drugs, mefenamic acid (MA), niflumic acid (NA), mesalazine (MS) and sulfasalazine (SS) in pure form and in their pharmaceutical formulations. The first method was based upon the kinetic investigation of the oxidation reaction of each drug (MA, NA, MS and SS) with alkaline potassium permanganate at room temperature for fixed time yielding a green color of manganate ion. The reaction is monitored by measuring the rate of change of absorbance of the resulting manganate species at 610 nm. The second method is based upon the reaction of carboxylic acid group of MA and NA with a mixture of potassium iodate (KIO3) and potassium iodide (KI) at room temperature. The reaction is followed by measuring the increase in absorbance at 352 nm as a function of time. The third method is based upon the oxidation reaction of MS and SS with a mixture of iodine and potassium iodide (KI) at room temperature. The light brown color is followed by measuring the increase in absorbance at 496 nm as a function of time. The initial-rate and fixed-time methods were adopted for constructing all the calibration curves. The proposed methods are validated statistically and through recoveries studies to confirming that there is no significant difference between the proposed methods and the reference method.