title: 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).
authors.affiliation: PreClinical Development Drug Metabolism and Pharmacokinetics, GlaxoSmithKline Research and Development, Ware, Hertfordshire SG12 0DP, UK. neil.spooner@gsk.com
authors.forename: Neil
authors.initials: N
authors.lastname: Spooner
authors.forename: Rakesh
authors.initials: R
authors.lastname: Lad
authors.forename: Matt
authors.initials: M
authors.lastname: Barfield
mesh_terms: D000082:Acetaminophen / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D001774:Blood Chemical Analysis / Q000379:methods*; D001775:Blood Circulation; D001800:Blood Specimen Collection / Q000379:methods*; D002986:Clinical Trials as Topic; D064420:Drug-Related Side Effects and Adverse Reactions; D005965:Glucuronates / Q000097:blood / Q000378:metabolism; D006801:Humans; D038622:Internationality; D016014:Linear Models; D004364:Pharmaceutical Preparations / Q000097:blood*; D010599:Pharmacokinetics; D012680:Sensitivity and Specificity; D013696:Temperature
chemical_list: D005965:Glucuronates; D004364:Pharmaceutical Preparations; C026317:glucuronamide; D000082:Acetaminophen