![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
Phenytoin is used in the prevention and treatment of seizures. It is important to measure the concentrations of both phenytoin and its major metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) to fully describe the pharmacokinetics of phenytoin in patients. The method utilized a Water 10 μm μBondapak C-18 column, a mobile phase containing 45% acetonitrile and 55% distilled water, and a detection wave length of 230 nm. The retention times of p-HPPH, and phenytoin, and internal standard, 5-(4-methylphenyl)-5-phenyl-hydantoin (TPH) were 4.2, 6.4, and 8.1, minutes respectively. The correlation coefficients for p-HPPH and phenytoin were 0.999 for both compounds. The accuracy of the method ranged from 98.8 to 108.8% for p-HPPH and from 94.3 to 102.1% for phenytoin at concentrations ranging from 0.05 to 0.35 mg/mL for each compound. The coefficient of variation ranged from 0.1 to 9.6% for p-HPPH and 0.8 to 5.0% for phenytoin. This method was successfully used to quantify phenytoin and p-HPPH in the urine of critically ill infants and children.