Highly sensitive UHPLC–DAD method for simultaneous determination of two synergistically acting antiepileptic drugs; levetiracetam and lacosamide: Application to pharmaceutical tablets and human urine

Abstract

A simple and highly sensitive ultra‐high‐performance liquid chromatographic–diode array (UHPLC‐DAD) detection method was developed and validated for the simultaneous estimation of levetiracetam (LEV) and lacosamide (LAC). It was clinically proven that the combination of LEV and LAC exhibits a synergistic effect against refractory seizures in mice, which was the motivation for the analysis of this binary mixture both in bulk and in human urine samples. The binary mixture was resolved on a Hypersil BDS C18 analytical column, utilizing a mobile phase of 0.050 mol L−1 phosphate buffer (pH 5.60), methanol and acetonitrile in the ratio (80:10:10 v/v/v) using catechol as an internal standard. The mobile phase was pumped at a flow rate of 1.2 mL min−1 with diode array detection at 205 nm for both drugs and 270 nm for IS. Calibration curves were linear with correlation coefficient >0.9990 over the studied concentration range of 0.1–70.0 μg mL−1 for both drugs. The developed method was reproducible with low relative standard deviation values for intra‐ and inter‐day precision (<2.0%). Both drugs were determined in bulk, pharmaceutical formulations and human urine samples without any interference from complex matrices.

Development of magnetic molecularly imprinted polymers for the extraction of salivary pepsin prior to analysis by a novel HPLC-SEC method

“…Minor changes applied to the chromatographic conditions such as flow rate, pH and concentration of mobile phase did not affect the method performance as indicated by calculating the percentage of recovery obtained from each minor change from the linear fit equation. Sensitivity of the developed method was determined practically by measuring LOD and LOQ from the signal to noise (S/N) ratio as conducted before in one of our previous works [26], where LOQ was found to be 0.25 µg mL -1 and LOD was 0.10 µg mL -1 . The collective values for method validation are tabulated in Table 3.…”

New Methods Used in Pharmacokinetics and Therapeutic Monitoring of the First and Newer Generations of Antiepileptic Drugs (AEDs)

“…Several years ago, LC-MS/MS was developed that allows the rapid quantification of LEV and its carboxylic metabolite in human plasma [104]. Simple UHPLC method with DAD detection was validated for determining LEV without any interference from complex matrices like urine [107]. The spectrofluorimetric method has been developed for LEV determination in plasma using derivatization procedure [105].…”

Development and evaluation of a simple and easy high‐performance liquid chromatography–ultraviolet system simultaneously suitable for determination of 24 anti‐epileptic drugs in plasma

“…In addition, only a limited number of the newer AEDs are quantifiable by the technique [5,18]. Chromatographybased methods, which can fulfill simultaneous separation, and accurate and sensitive determination of multiple compounds, have been widely implemented in the TDM of AEDs, such as GC coupled with flame ionization [19], electron capture [20], nitrogen-phosphorus [20] or MS detector [21], HPLC or UHPLC coupled with UV-visible (UV-VIS) [22], electrochemical [23], fluorescence [24] or mass spectrometry (MS) detector [13,25], and high-performance CE (HPCE) [26]. Among those methods, for its lower cost and higher applicability for most drugs, HPLC-UV is more suitable than the others for TDM of AEDs in most hospitals, especially primary hospitals in developing countries [18,[27][28][29].…”