Two simple, rapid, sensitive, low-cost, and accurate methods (A and B) for the microdetermination of amantadine HCl (AMD) in pure form and in pharmaceutical formulations are developed. Method A is based on the formation of tris (o-phenanthroline)-iron(II) complex (ferroin) upon reaction of amantadine HCl with an iron (III)-o-phenanthroline mixture in sodium acetate-acetic acid buffer media. The ferroin complex is spectrophotometrically measured at λmax 509nm against reagent blank. Method B is based on the reduction of Fe (III) by the drug which forms colored complex (λmax 521nm) with 2,2′-bipyridyl. Optimizations of the experimental conditions are described. Beer’s law is obeyed in the concentration ranges 0.4–10 and 0.6–22μgmL−1 using 1,10-phenanthroline and 2,2′-bipyridyl, respectively. The developed methods have been successfully applied for the determination of AMD in bulk drugs and in pharmaceutical formulations. The common excipients and additives did not interfere in their determinations.
Arab. J. Chem. 4 (2011) 287–292.