Polarographic determination of phenytoin and benzophenone (as impurity) in pharmaceutical preparations.
A differential pulse polarographic method is described for detection and trace determination of benzophenone (the main impurity) in phenytoin powder. The method depends upon the polarographic activity of benzophenone in Britton-Robinson buffer pH 5.6. The limit of detection was found to be 2.5 x 10(-6) microg ml(-1). Phenytoin has been analysed polarographically after oxidation with alkaline permanganate to give benzophenone; the limit of detection was found to be 6 x 10(-6) microg ml(-1).
Razak
Omayma A
OA
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, University of Alexandria, EL-Messalah 21521, Egypt.
Gazy
Azza A
AA
Wahbi
A M
AM
D001577:Benzophenones / Q000032:analysis*; D002138:Calibration; D002214:Capsules; D007202:Indicators and Reagents; D010084:Oxidation-Reduction; D010672:Phenytoin / Q000032:analysis*; D011048:Polarography; D011208:Powders; D015203:Reproducibility of Results; D013535:Suspensions; D013696:Temperature
D001577:Benzophenones; D002214:Capsules; D007202:Indicators and Reagents; D011208:Powders; D013535:Suspensions; D010672:Phenytoin