Preconcentration and Quantification of Pregabalin in Plasma using Capillary Electrophoresis

Abstract

Background: A micellar electrokinetic chromatographic (MEKC)/ indirect UV detection method with hydrodynamic and electrokinetic injection has been developed for the determination of pregabalin in the aqueous samples. Aim: Determination of pregabalin in plasma sample with an indirect UV detection using capillary electrophoresis and investigating the effects of preparation methods consist of protein precipitation and all of kind liquid-liquid micro extraction method on the extraction of pregabalin. Method: Separation of the drug was achieved on Agilent capillary electrophoresis in less than 5 min using a 50 cm × 75 μm i.d. uncoated fused-silica capillary and a background electrolyte (BGE) consisting of 5-aminosalicylic acid (5-ASA, 10 mmol L-1), cetyl trimethylammonium bromide (CTAB, 1 mmol L-1) and tri-sodium citrate (4% v/v). The influence of various parameters on the separation such as separation voltage, injection time, cassette temperature, pH of BGE and organic modifier was investigated. Results: Method validation shown good linearity (R2> 0.999) in the range of 1.5-100 µg mL-1 of pregabalin. A limit of detection (LOD) of 0.8 μg mL-1 and a limit of quantitation (LOQ) of 2.6 μg mL-1 were reported for pregabalin. Conclusion: The proposed method was found to be suitable and accurate for the determination of pregabalin in aqueous samples, but this method is not applicable for quantification of pregabalin to therapeutic drug monitoring whereas structure of analyte is completely hydrophilic therefore the routine liquid-liquid micro extraction methods are not practicable to extraction of analyte. Mesalazin was used as a probe with high molar absortivty in composition of background electrolyte.