HPLC quantification of metoprolol with solid-phase extraction for the drug monitoring of pediatric patients

✍ Scribed by Stefanie Albers; Jan-Peer Elshoff; Christina Völker; Andrea Richter; Stephanie Läer

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 136 KB
• Volume: 19
• Category: Article
• ISSN: 0269-3879
• DOI: 10.1002/bmc.436

✦ Synopsis

Although the analytical literature seems abundant for the determination of metoprolol in human plasma, a method using standard equipment providing a sensitive and simple high-performance liquid chromatographic (HPLC) method for limited blood volume, e.g. where 1 mL of blood in a 1 kg infant equals 70 mL of adult blood volume, has rarely been addressed. Therefore, in 500 µL of plasma, metoprolol was extracted using an internal standard and solid-phase extraction columns. Chromatographic analysis was performed on a Spherisorb C 6 column (5 µm particle size) at ambient temperature and fluorimetric detection with an excitation wavelength of 225 nm, and emission wavelength of 310 nm. The mobile phase [30% acetonitrile and 70% 0.25 m potassium acetate buffer (pH 4)] was pumped with 1 mL/min. Metoprolol recovery was determined at 73.0 ± 20.5%, and the limit of quantitation was 2.4 ng/mL. Precision values of intra-and inter-assay were below 15.5% and those for accuracy were between 90 and 110%. This method was developed for monitoring and determination of pharmacokinetic parameters of metoprolol in pediatric patients and therefore metoprolol plasma concentrations in a 2-year-old child with ventricular tachycardia are reported.