Phenytoin, approved by the Food and Drug Administration in 1999 as a sedative for use in the intensive care unit, is a potent and highly selective α2-adrenoceptor agonist with significant sedative, analgesic and anxiolytic effects mostly used in the intensive care units. This article describes validation for the determination of related substances of Phenytoin Sodium in Phenytoin Sodium Capsules by usinga high performance liquid chromatography. The high performance liquid chromatography resolution was achieved on an Inertsil ODS 3, 150 x 4.6mm, 5µm, column with an gradient elution at a flow rate of 1.0 mL/min using a mobile phase A as buffer and mobile phase B as acetonitrile. The detection was performed by a photo diode array Detector. The method was validated in the concentration range of Limit of quantitation to 150% of working concentration. The intra and inter-day precision and accuracy were within Limit (10 % Relative Standard Deviation). The overall mean recoveries of Phenytoin were 97.5% for Limit of Quantitation and 95.6 % for 50% to 150%.
