A Micellar Electrokinetic Chromatography Screening Tool for Antiepileptic Drugs

This study presents an affordable micellar electrokinetic chromatography (MEKC) method for the simultaneous analysis of six commonly used antiepileptic drugs: ethosuximide, phenobarbital, lamotrigine, phenytoin, carbamazepine, and diazepam. Systematic optimization of the method resulted in a running buffer containing 80 mM sodium dodecyl sulfate, 5% methanol, 2.5 mM phosphate, and 10 mM borate at pH 8.7, which provided robust and reliable separation. The method demonstrated excellent precision, with migration time %RSD values below 2% for both intraday and inter-day repeatability, and peak area %RSD values within acceptable limits (1.7%-3.7% intraday; 2.9%-6.3% inter-day). Linearity was confirmed for all analytes, with r² values exceeding 0.99 and residuals randomly distributed around zero. Robustness testing showed that small variations in electrophoretic conditions did not significantly affect the resolution of the critical analyte pairs, which consistently remained above 1.5. Application of the method to five antiepileptic tablet formulations obtained from the Ethiopian market demonstrated its suitability as a rapid, reliable, and cost-effective screening tool. Overall, the developed MEKC method provides a practical analytical approach for antiepileptic medicines' quality assessment in resource-limited settings, supporting efforts to strengthen regulatory surveillance and safeguard public health.