Sensitive liquid chromatography/tandem mass spectrometry method for the simultaneous determination of seventeen beta blockers

Abstract

In recent years, examples of drugs responsible for acute drug intoxication in elderly people include benzodiazepines, phenobarbital, digitalis preparations, phenytoin, beta blockers or calcium antagonists, and antidepressants in Japan. Due to the diversity of underlying diseases, the reasons for this include increasing number of prescription medicines due to regular oral medicines themselves interacting, and age-related changes in drug metabolism. Beta blockers for clinical use are employed in the management of a range of disorders, including hypertension, heart failure, arrhythmias, migraine headache and tremor. Beta blockers are prescribed widely and also have a high frequency of accidental ingestion by the elderly people. Cardiovascular drugs (beta blockers) present more serious symptoms of intoxication than the underlying diseases themselves. The aim of this study is to develop and validate a sensitive liquid chromatography–tandem mass spectrometry (LC-MS/MS) with ESI method for the simultaneous determination of seventeen beta blockers (atenolol, carteolol, nadolol, pindolol, timolol, acebutolol, arotinolol, metoprolol, esmolol, celiprolol, labetalol, bisoprolol, propranolol, alprenolol, betaxolol, bevantolol and carvedilol). The extractions of beta blockers in human serum were performed by solid-phase extraction method using Oasis® PRiME HLB column (Waters). LC-MS/MS experiments were performed with a HPLC system, which consisted of Shimadzu LC-20AD pumps, a SIL-20AC autosampler and the 4000 QTRAP mass spectrometer (AB SCIEX). The chromatographic separation was performed on a Mightysil-RP-18 MS column (150 × 2.0-mm i.d., 5 μm). For the gradient elution, two solvents were used: (A) 10 mM acetic ammonium buffer and (B) acetonitrile. The flow rate was 0.20 mL/min and the column and autosampler were maintained at 37 and 4˚C, respectively. The settings of the turbo ion-spray were as follows; curtain gas, N2:40 psi, collision gas, N2:4 psi, collision energy: 27∼41 V, ion-spray voltage: 5500 V, ionization mode: ESI positive, source temperature: 600˚C. Separation and sensitivity for the detection of seventeen beta blockers by LC-MS/MS were sufficient and the precursor [M + H]+ ion was detected in the mass spectrum for each drug. This method had a chromatographic total run time of 15 min. The calibration curves were linear over the concentration range of 20–400 ng/mL for seventeen beta blockers (r = 0.9686∼0.9997). The extraction yields of human serum sample with Oasis® PRiME HLB column were ranged from 66.1 to 93.5%, the precision within 0.07 CV values were acceptable of this method. But the extraction yields of bevantlol (37.5%) and carvedilol (26.2%) were low. Currently, we are experimenting to improve the extraction yields of bevantolol and carvedilol. Phyo Lwin EM, et al (2017, Bioanalysis.) developed a method for the determination of atenolol in human plasma and milk sample by LC-MS/MS. The limits of detection (LOD) and quantification (LOQ) were in the range 1.0 ng/mL and 5.0 ng/mL for atenolol. Our LC-MS/MS with ESI method was able to measure compounds at approximately the same concentrations as the analytical methods of Phyo Lwin EM, et al. In our experiments, LOD and LOQ in the range 0.0034–1.6 ng/mL and were 20 ng/mL for seventeen beta blockers. The presently established method is very useful for simultaneous measurements of beta blockers in human serum by LC-MS/MS in clinical and forensic investigations.