Automated high throughput analysis of antiretroviral drugs in dried blood spots

Abstract

For therapeutic drug monitoring in remote settings, dried blood spots (DBS) are particularly advantageous, as blood sample collection and handling is uncomplicated. The aim of this study was to develop and validate an automated extraction method for the analysis of nevirapine, efavirenz and lopinavir in DBS samples. Automated extraction was performed with methanol : water (70 : 30 v/v), using a DBS-MS 500 autosampler coupled to a liquid chromatography tandem mass spectrometry system. The autosampler used digital images of each DBS to position the extraction head, sprayed 10 μl of internal standard onto each DBS and extracted a 4-mm disc (Ø) from the centre of each spot by unilateral flow using 25-μl extraction solvent. The analytes were baseline separated on a pentafluorophenyl column and analysed by using electrospray ionization with multiple reaction monitoring in positive polarity mode for nevirapine and lopinavir and in negative mode for efavirenz. The method was linear between 10 and 10 000 ng/ml for all analytes. Automated sample extraction resulted in consistent recoveries (nevirapine: 70 ± 6%, efavirenz: 63 ± 11% and lopinavir: 60 ± 10%) and matrix effects between different donors and concentration levels. Intra-day and inter-day accuracy and precision deviations were ≤15%. Manual and automated extractions of DBS samples collected within the framework of an adherence assessment study in rural Tanzania showed good agreements with deviations of less than 10%. Our study highlights that therapeutic drug monitoring samples obtained in the resource-constrained setting of rural Africa can be reliably determined by automated extraction of DBS. Overall, automatization improved method sensitivity and facilitates analysis of large sample numbers. Copyright © 2017 John Wiley & Sons, Ltd.

Fully automated drug screening of dried blood spots using online LC-MS/MS analysis

“…After a 20 second drying time the samples were extracted with a volume of 20 μL and a 200 μL/min flow rate. To complete the automated DBS extraction cycle, the system was rinsed for 20 seconds [14].…”

“…Additionally a morphine signal was detectable in the patient taking codeine, since typically approximately 10 % of the codeine is metabolized via CYP2D6 to morphine [24]. The internal standards are used to monitor the extraction efficiency and to ensure that the system is working properly [14,25]. 20 μL of the internal standard mix was sprayed on the DBS spot prior extraction.…”

“…The DBS technology emerged to further applications and markets such as therapeutic drug monitoring [3][4][5], pharmaco-toxicokinetic studies [6] and forensics [7][8][9][10][11][12][13]. Advantages of using DBS are simplified blood collection, reduced shipping, and storage costs and reduced analysis time and labor costs due to full automation [4,14]. Automation of the DBS workflow was achieved by automated punching equipment [15], where a manual transfer step of transporting the discs remains, and by direct elution technologies [16,17].…”

Extended and Fully Automated Newborn Screening Method for Mass Spectrometry Detection

“…DBS cards were dried at room temperature for at least 3 h and were subsequently stored at 4 • C in sealed plastic bags containing desiccants. All DBS were prepared from the same blood source, prepared with the same procedure to neutralize potential hematocrit effect [12,13], which were not investigated in this study.…”

Estudo de estabilidade de drogas de abuso e medicamentos de interesse forense em >i<DRIED BLOOD SPOT>/i<

“…Assim, em virtude das razões mencionadas, é desejável a associação entre a amostragem por DBS e análise por espectrometria de massas, devido à sensibilidade, seletividade e automação adequadas aos propósitos analíticos, e, por isso, a busca por trabalhos científicos relacionados à análise de diferentes tipos de substâncias mostra a grande aplicação dessa associação (KOSTER et al, 2017;PAGE-SHARP et al, 2017;LA MARCA et al, 2012;ROSTING, 2017;FERRONE et al, 2017;DUTHALER et al, 2017;CALCAGNO et al, 2015;GARCIA BOY et al, 2008;JANTOS et al, 2011).…”