Dried Blood Spots as a Sample Collection Technique for the Determination of Pharmacokinetics in Clinical Studies: Considerations for the Validation of a Quantitative Bioanalytical Method

Abstract

A novel approach has been developed for the quantitative determination of circulating drug concentrations in clinical studies using dried blood spots (DBS) on paper, rather than conventional plasma samples. A quantitative bioanalytical HPLC-MS/MS assay requiring small blood volumes (15 microL) has been validated using acetaminophen as a tool compound (range 25 to 5000 ng/mL human blood). The assay employed simple solvent extraction of a punch taken from the DBS sample, followed by reversed phase HPLC separation, combined with selected reaction monitoring mass spectrometric detection. In addition to performing routine experiments to establish the validity of the assay to internationally accepted criteria (precision, accuracy, linearity, sensitivity, selectivity), a number of experiments were performed to specifically demonstrate the quality of the quantitative data generated using this novel sample format, namely, stability of the analyte and metabolites in whole human blood and in DBS samples; effect of the volume of blood spotted, the device used to spot the blood, or the temperature of blood spotted. The validated DBS approach was successfully applied to a clinical study (single oral dose of 500 mg or 1 g acetaminophen).

A validated method for the quantification of fosfomycin on dried plasma spots by HPLC–MS/MS: Application to a pilot pharmacokinetic study in humans

“…The validation was performed in accordance with the guidelines provided by the US FDA with pre-established acceptance criteria required to demonstrate the method is suitable for the intended purpose [30] and current scientific standards on microsampling [31][32][33]. The validation for extraction of fosfomycin from dried plasma spots was assessed for lower limit of quantification (LLOQ), linearity, inter-day precision and accuracy, sample spot volume, matrix effects, recovery, storage and transport stability.…”

Farmacocinética comparada de metformina, en forma sólida y en formulación extemporánea líquida para pediatría, en voluntarios adultos sanos

“…En la segunda etapa, después de un período de eliminación total del fármaco de una semana (periodo de lavado), 18 los primeros 6 voluntarios tomaron la media tableta de metformina y los restantes tomaron la formulación extemporánea. De este modo, cada voluntario fue su propio testigo.…”

“…[14][15][16][17][18][19] Esta técnica es muy poco invasiva ya que, sin necesidad de canalizar, se pueden obtener múltiples muestras sanguíneas de muy pequeño volumen, con la punción del talón o el dedo y se transfieren a papel filtro, donde se almacenan y se pueden analizar mucho tiempo después. Originalmente se planeó para detectar enfermedades metabólicas en el recién nacido.…”

Rapid and sensitive LC–MS/MS method for the analysis of antibiotic linezolid on dried blood spot

“…An attracting and potential method to easily obtain samples for PK studies and TDM in children is collection of whole blood samples onto filter paper (dried blood spot or DBS) [7][8][9][10][11][12]. DBS are commonly used for neonatal screening of metabolic diseases, cystic fibrosis and hypothyroidism in micro-blood samples.…”

“…DBS are commonly used for neonatal screening of metabolic diseases, cystic fibrosis and hypothyroidism in micro-blood samples. Some studies recently evaluated the use of DBS for TDM and toxicology in adults [7][8][9][10][11][12]. Some authors, also from our group, applied the DBS technique to evaluate drug concentrations in newborns, infants and children [7][8][9][10][11][12].…”