Extraction of metoprolol from some biological samples with modified magnetic iron oxide nanoparticles and determination by spectrofluorimetry

Abstract

Background: Metoprolol is a selective β1-adrenergic receptor antagonists (β-blocker). It is widely used for the treatment of hypertension and other related diseases. Metoprolol can be used as a doping agent in sport, thus has been added to the list of forbidden drugs. Therapeutic drug monitoring (TDM) of β-blockers is an applied procedure in some cases. Using a simple and low-cost analytical procedure may help to use TDM in routine clinical practice. Aim: The synthesized MNPs were modified with SDS surfactant and employed as sorbent in MSPE of metoprolol in different biological samples before it determination by using spectrofluorimetry. Method: A real biological sample was prepared and adjusted to pH 3-4, then metoprolol was quickly extracted using iron oxide magnetic nanoparticles (IOMNPs) modified by the surfactant SDS and determined applying spectrofluorimetry at 340 ± 3 nm after excitation set at 283 ± 3 nm. Results: The extraction and determination conditions including, the amount of MNPs and SDS, pH of solution, extraction and desorption time, solvent type and tis volume were adjusted. Calibration curves were linear over the concentration range 6–100 ng/mL for plasma and 5–100 ng/mL for water, urine and exhaled breath condensate (EBC) samples, respectively. Intra and inter-day precision values for metoprolol in different samples were less than 5.6 % and 6 %, respectively, and accuracy (as relative error) was better than 5 %. Standard addition recovery tests were carried out, and the analytical recoveries ranged from 86 % to 113 %. The limits of detection (LOD) and limits of quantification (LOQ) of metoprolol were found to be in the range of 2.1-3.4 ng/mL and 6.3-10.2 ng/mL, respectively. Conclusion: The developed method was successfully applied to one volunteer with hypertension who had been given an oral tablet of 50 mg metoprolol