title: Simultaneous determination of phenytoin and carbamazepine in human hair by high-performance liquid chromatography.
abstract: Drug detection in human hair has been regarded as a potentially useful technique for therapeutic drug monitoring and for the assessment of therapeutic compliance. An isocratic high-performance liquid chromatography (HPLC) assay for the simultaneous measurement of phenytoin and carbamazepine in human hair was used to assess therapeutic compliance in a population of patients with epilepsy. After alkaline digestion, phenytoin and carbamazepine were separated on a reverse-phase column by using a mobile phase of acetonitrile/methanol/water (9:37:54) and monitored at a wavelength of 214 nm with methylphenyl-5-phenylhydantoin as internal standard. The assay was linear in the range from 0 to 66.66 ng/mg hair, and recoveries of both drugs at concentrations of 8.33, 33.3, and 66.66 ng/mg hair from the hair matrix ranged from 91.2 to 104.0%. Inter- and intraassay coefficients of variation for both drugs (assessed at three concentrations in the calibration range) were < 10%. The limits of detection for phenytoin and carbamazepine were 2.0 and 1.33 ng/mg hair, respectively.
authors.affiliation: Department of Pharmacology and Therapeutics, University of Wales, College of Medicine, Heath Park, Cardiff, U.K.
authors.forename: Z
authors.initials: Z
authors.lastname: Mei
authors.forename: J
authors.initials: J
authors.lastname: Williams
mesh_terms: D000927:Anticonvulsants / Q000032:analysis*; D002220:Carbamazepine / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D006197:Hair / Q000737:chemistry*; D006801:Humans; D010672:Phenytoin / Q000032:analysis*
chemical_list: D000927:Anticonvulsants; D002220:Carbamazepine; D010672:Phenytoin