Spectrophotometric Determination Mefenamic Acid , in Pharmacutical Preparation by oxidative coupling 2,4,dinitrophenyl hydrazine by N-bromo succinmide


This eserech includes the development of spectrophotometric method for determination of mefenamic acid via oxidative coupling with the 2,4,dinitrophenyl hydrazine reagent in presence of oxidizing agent N-bromo succinmide in the alkaline medium to form a colored-dye red, which dissolved in water and showed the highest intensity of absorption at λmax 528 nm. The method has been obeyed Beer's law in the concentration range 2-8 µg.ml-1, with molar absorptivity of 3.6873 ×104 L. mol-1. cm-1, Sandel Index value 0.006535 µg.cm-2, the detection limited 0.011 µg.ml-1, with correlation coefficient 0.992. The relative standard deviation of the method does not exceed 2.27%. The proposed method was applied successfully for the determination of Mefenamic acid in tablets by both the direct and standard addition methods, the recovery ranged between 99.3-100.2%.