Colorimetric determination of acetylcysteine, penicillamine, and mercaptopropionylglycine in pharmaceutical dosage forms.
A colorimetric determination of acetylcysteine, penicillamine, and mercaptopropionylglycine is described. The method is based on the oxidation of mercapto-compounds with iron(III) in the presence of 1,10-phenanthroline. The iron(II) formed was quantitatively and rapidly converted to the stable tris(1,10-phenanthroline)iron(II) complex measured spectrophotometrically at 515 nm. The results obtained from various commercial formulations indicate that the method proposed allows a simple, sensitive determination of these mercapto-drugs with good accuracy (99.5-101% recovery) and remarkable precision (RSD +/- 0.6-1.6%).
D000111:Acetylcysteine / Q000032:analysis*; D000603:Amino Acids, Sulfur / Q000032:analysis*; D002214:Capsules / Q000032:analysis; D003124:Colorimetry / Q000379:methods; D010396:Penicillamine / Q000032:analysis*; D012996:Solutions / Q000032:analysis; D013053:Spectrophotometry; D013607:Tablets / Q000032:analysis; D008625:Tiopronin / Q000032:analysis*
D000603:Amino Acids, Sulfur; D002214:Capsules; D012996:Solutions; D013607:Tablets; D008625:Tiopronin; D010396:Penicillamine; D000111:Acetylcysteine