TY - JOUR
T1 - Development and Validation of a Highly Sensitive Liquid Chromatography-Tandem Mass Spectrometry Technique to Determine Levamisole in Plasma and Saliva
AU - LEARNS consortium
AU - Veltkamp, Floor
AU - Pistorius, Marcel C. M.
AU - Bouts, Antonia H. M.
AU - Mathôt, Ron A. A.
N1 - Publisher Copyright: Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved. Copyright: This record is sourced from MEDLINE/PubMed, a database of the U.S. National Library of Medicine
PY - 2021/4/1
Y1 - 2021/4/1
N2 - BACKGROUND: Levamisole is used as a steroid-sparing drug for the treatment of frequently relapsing or steroid-dependent idiopathic nephrotic syndrome in children. As part of a large multicentre randomized controlled trial with levamisole, pharmacokinetic and pharmacodynamic parameters of levamisole in children with idiopathic nephrotic syndrome were investigated, as well as the feasibility of using saliva as an alternative and patient-friendly matrix for determining levamisole concentrations. In this study, the authors presented the development and validation of a highly sensitive method for determining levamisole in plasma and saliva using liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: In 100 μL samples, proteins were precipitated with 750 μL acetonitrile/methanol 420:80 (v/v) with levamisole-D5 as an internal standard. Calibration standards were prepared over a range of 0.1 ng/mL-50 ng/mL. To determine ultrafiltration efficiency, the ultrafiltrate was obtained by centrifuging blank plasma samples over the filter. Both filtered and nonfiltered samples were analyzed. RESULTS: For plasma, accuracy and within-run and between-run imprecision were between 95.0% and 100% and <14.5%, respectively, and for saliva, between 100.9% and 107.5%, and <13.3%. No significant matrix effects were observed. Samples were stable at benchtop for 24 hours and -80°C, for at least 14 months (stability experiments ongoing). The ultrafiltration efficiency of unbound concentrations in plasma was lower than 85% (58.9%) but stable, and, therefore, the observed concentration should be corrected. CONCLUSIONS: Based on observations, the developed measure can determine levamisole concentrations in participant saliva samples.
AB - BACKGROUND: Levamisole is used as a steroid-sparing drug for the treatment of frequently relapsing or steroid-dependent idiopathic nephrotic syndrome in children. As part of a large multicentre randomized controlled trial with levamisole, pharmacokinetic and pharmacodynamic parameters of levamisole in children with idiopathic nephrotic syndrome were investigated, as well as the feasibility of using saliva as an alternative and patient-friendly matrix for determining levamisole concentrations. In this study, the authors presented the development and validation of a highly sensitive method for determining levamisole in plasma and saliva using liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: In 100 μL samples, proteins were precipitated with 750 μL acetonitrile/methanol 420:80 (v/v) with levamisole-D5 as an internal standard. Calibration standards were prepared over a range of 0.1 ng/mL-50 ng/mL. To determine ultrafiltration efficiency, the ultrafiltrate was obtained by centrifuging blank plasma samples over the filter. Both filtered and nonfiltered samples were analyzed. RESULTS: For plasma, accuracy and within-run and between-run imprecision were between 95.0% and 100% and <14.5%, respectively, and for saliva, between 100.9% and 107.5%, and <13.3%. No significant matrix effects were observed. Samples were stable at benchtop for 24 hours and -80°C, for at least 14 months (stability experiments ongoing). The ultrafiltration efficiency of unbound concentrations in plasma was lower than 85% (58.9%) but stable, and, therefore, the observed concentration should be corrected. CONCLUSIONS: Based on observations, the developed measure can determine levamisole concentrations in participant saliva samples.
UR - http://www.scopus.com/inward/record.url?scp=85102964566&partnerID=8YFLogxK
U2 - https://doi.org/10.1097/FTD.0000000000000811
DO - https://doi.org/10.1097/FTD.0000000000000811
M3 - Article
C2 - 32910097
SN - 0163-4356
VL - 43
SP - 279
EP - 285
JO - Therapeutic drug monitoring
JF - Therapeutic drug monitoring
IS - 2
ER -