HAEMATOXYLIN-PERMANGANATE REAGENT FOR THE SPECTROPHOTOMETRIC DETERMINATION OF SOME THIOL DRUGS

Document Type : Original Article

Author

Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt

Abstract

A new rapid and sensitive spectrophotometric method was developed for the determination of six thiol pharmaceutical compounds. The method is based on the spontaneous oxidation of the thiol group with a constant small concentration of potassium permanganate followed by the rapid reaction of the excess permanganate with haematoxylin reagent in neutral aqueous medium. Haematoxylin is oxidized to the coloured chromogen, haematein which was measured at 558 nm. A linear relationship was obtained between drug concentration and the decrease in absorbance readings. The method was applied for the determination of the investigated compounds either in authentic powders or in some .dosage forms. Good agreement was obtained with the reported methods. In addition, the suggested method was tried as stability indicating assay for the investigated thiol drugs.