AMMONIUM MOLYBDATE AS A SPECTROPHOTOMETRIC REAGENT FOR THE DETERMINATION OF INDOMETHACIN IN PURE AND PHARMACEUTICAL PREPARATIONS

ABSTRACT

Indomethacin reacts with ammonium molybdate in concentrated hydrochloric acid to give a violet colour after heating for 5 min at 100°C having maximum absorbance at 550 nm. The reaction is selective for indomethacin with 0.01 mg/10 mL as visual limit of identification and provides a basis for a new spectrophotometric determination. The reaction obeys Beer's Law from 0.01 mg to 3 mg/10 mL of indomethacin and the relative standard deviation for 0.01 mg of indomethacin is 0.71%. The quantitative assessment of common interferences and tolerable amount of other drugs is also studied.

Keywords:

• Indomethacin
• Ammonium molybdate
• Spectrophotometer

Acknowledgments