Determination of free and total levels of phenytoin in human plasma from patients with epilepsy by MEKC: An adequate alternative to HPLC
✍ Scribed by Ping-Chih Lin; Ya-Hui Hsieh; Fen-Fen Liao; Su-Hwei Chen
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 351 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0173-0835
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
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×HPLC+0.0976, r^2^=1; for free level: MEKC=1.0013×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.