A simple and cost-effective HPLC-UV method for the detection of levetiracetam in plasma/serum of patients with epilepsy

A simple, fast and cost-effective method was developed and validated for the determination of levetiracetam (LEV) in plasma/serum of patients using high performance liquid chromatography (HPLC) with ultraviolet detection. The stability of LEV plasma/serum samples over time and in different blood collection tubes was evaluated. Serum/plasma samples were deproteinized by methanol spiked with the internal standard, gabapentin. HPLC was carried out on a Venusil XBP C-18, 250x4.6mm, 5m column, at a flow rate of 1.0mL/min and with mobile phase consisting of 50mm potassium dihydrogen phosphate-acetonitrile at a pH of 5.5. The UV detector was set at 205nm and 10L was injected. Total runtime was 15min. Calibration curves were linear (correlation coefficient=0.999) over a concentration range of 1-60g/mL. Relative standard deviation values for both the inter-day and intra-day precision and accuracy were <5% for the concentration range. The influence of different collection tubes and the effect of time on the stability of LEV was investigated. These factors may cause inaccuracies owing to drug-protein binding and interference in the matrix. This method is simple, fast, cost-effective, reliable and accurate with minimal sample preparation for daily routine use in therapeutic drug monitoring.