Phenytoin free fraction determination: comparison of an improved direct serum injection high-performance liquid chromatographic method to ultrafiltration coupled with fluorescence polarization immunoassay.
Recent developments in restricted-access media (RAM) liquid chromatography make the simultaneous determination of total and free phenytoin concentrations possible by direct injection of drug-containing serum samples. A comparison of phenytoin free fraction determination by ultrafiltration coupled with fluorescence polarization immunoassay (TDX) to an improved direct injection RAM-HPLC method is presented. Our improved method differs from those previously reported with regard to column type, mobile-phase composition, and column temperature. Replicate samples analyzed by each method yielded similar values for serum phenytoin free fraction.
Department of Pharmaceutics, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock 72205, USA.
B J
BJ
Gurley
M
M
Marx
K
K
Olsen
D000927:Anticonvulsants / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D010672:Phenytoin / Q000097:blood*; D013056:Spectrophotometry, Ultraviolet; D014462:Ultrafiltration
D000927:Anticonvulsants; D010672:Phenytoin