UTILITY OF OXIDATION-REDUCTION REACTION FOR THE SPECTROPHOTOMETRIC DETERMINATION OF ANTIVIRAL AND ANTI-PARKINSONIAN DRUG AMANTADINE HCl

Two simple, rapid, accurate, and sensitive spectrophotometric methods have been developed for the determination of amantadine HCl (AMD) in pure form and in pharmaceutical formulations. The first method is based on the reaction of the drug with potassium permanganate in the presence of sodium hydroxide to produce a water-soluble bluish-green colored species measurable at 610 nm. The absorbance concentration plot is linear over the range (0.2-6.5 μg/ml). The second method is based on oxidation of the drug by potassium permanganate in acidic medium, and determination of the unreacted oxidant by measuring the decrease in absorbance using two different dyes; methylene blue (MB) and amaranth dye (AM)) at a suitable λmax (662 and 520 nm), respectively. Regression analysis of Beer's law plots showed good correlation in the concentration ranges (0.1-5.0, 0.1-5.6 μg/ml), respectively. The apparent molar absorptivity, Sandell sensitivity, detection and quantitation limits were calculated for two methods. Statistical treatment of the results reflects that the proposed procedures are precise, accurate and easily applicable for the determination of amantadine HCl in pure form and in pharmaceutical preparations.