Determination of free and total levels of phenytoin in human plasma from patients with epilepsy by MEKC: An adequate alternative to HPLC

作者：Lin Ping Chih; Hsieh Ya Hui; Liao Fen Fen; Chen Su Hwei^*

来源：Electrophoresis, 2010, 31(9): 1572-1582.

DOI：10.1002/elps.200900768

• Epilepsy
• HPLC
• MEKC
• Phenytoin

Phenytoin is a widely used anti-seizure agent, and a good correlation is observed between its concentration in plasma and the clinical effect. We developed a selective CE with UV detection at 200 nm for analysis of free and total levels of phenytoin in human plasma based on MEKC. A sample pretreatment by liquid liquid extraction with ethyl acetate for determination of total level of phenytoin and serum ultrafiltrate was prepared by ultrafiltration technique (ultrafiltration membrane 30 kDa; 2000 g, 10 min) for determination of free level of phenytoin and subsequent quantification by MEKC was used. MEKC was performed in Tris buffer (25 mM; pH 10.5) containing SDS (180 mM) and EG (13%) as BGE. Hydrodynamic injection for phenytoin determination (0.5 psi 5 s for total level, 2 psi 5 s for free level) was used to introduce samples. The separation voltage was set at 20 kV. Data obtained by MEKC were compared with the results by a validated HPLC method. The MEKC assay of phenytoin exhibited a very good correlation with respect to HPLC by Bland-Altman method. The equations for the Passing-Bablok regression line were as follows: for total level: MEKC = 1.0143 x HPLC+0.0976, r(2) = 1; for free level: MEKC = 1.0013 x HPLC-0.0016, r(2) = 1. The proposed method was applied successfully to monitor free and total levels of phentoin in 20 patients with seizures.

• 出版日期2010-5