Preparation of Restricted Access Media-Methacrylic Resin and Its Application as the Sorbent of Solid-Phase Extraction in the Lamotrigine Determination in Human Plasma by HPLC–UV

Restricted Access Media-Methacrylic Resin with the ability of protein exclusion was prepared by the free radical polymerization using methacrylic acid, ethylene glycol dimethacrylate and glycidyl methacrylate as monomer, cross-linker and comonomer, respectively. Protein exclusion ability of this material was studied. The results showed that the material was able to eliminate 93.6% of protein after bovine serum albumin solution was added and shaken for 220 min. Adsorption kinetics and adsorption isotherms of Lamotrigine on this material were investigated. The experimental data were the most suitable for the pseudo-second-order kinetics model and Freundlich isotherm model. Restricted Access Media-Methacrylic Resin was used as sorbent for Solid-Phase Extraction to extract Lamotrigine from Human Plasma. The method for the determination of Lamotrigine in human plasma by SPE followed by the HPLC–UV presented linear range from 1.0 to 66.6 µg/mL with correlation coefficient 0.9930 for Lamotrigine, assay precision with relative standard deviation value 6.24%, and assay accuracy 94.7–104.7% with relative standard deviation values 4.33–5.81%. SPEs filled with this material were used at least 7 times without any significant changes in their performance. Analytical validation parameters demonstrated that the method could be applied to the determination of Lamotrigine at the therapeutic plasma levels without other treatments.