RESUMO
BACKGROUND: In the framework of wider exploration of the application of dried blood spots (DBS) in bioanalysis, by the DBS consortium of the European Bioanalytical Forum, one team of five laboratories investigated the merits of the various ways of IS addition prior to LC-MS/MS analysis. A set of 22 pharmaceutical compounds with log P in the range of 0-10 was selected for this purpose. Assessments were made of precision, recovery, and of the effects of prolonged storage. RESULTS: Assay precision was not significantly different for 3 month-aged samples as compared with 'fresh' samples stored for 7-22 days. Extraction recovery from 3 month-aged spots decreased for some of the analytes; the most widely employed addition of IS in the extraction solvent does not compensate for recovery in such cases. CONCLUSION: From the overall results, it is clear that there is no 'one size fits all' approach to IS addition in DBS bioanalysis.
Assuntos
Teste em Amostras de Sangue Seco/normas , Manejo de Espécimes/normas , Animais , Europa (Continente) , Humanos , Associações de Prática Independente , Metanol , Ratos , Reprodutibilidade dos Testes , Microextração em Fase Sólida , Solventes , Espectrometria de Massas em Tandem , Fatores de TempoRESUMO
The 5th GCC in Barcelona (Spain) and 6th GCC in San Antonio (TX, USA) events provided a unique opportunity for CRO leaders to openly share opinions and perspectives, and to agree upon recommendations on biomarker bioanalytical method validation.
Assuntos
Bioensaio/normas , Biomarcadores/análise , Calibragem , Cromatografia Líquida de Alta Pressão/normas , Serviços Contratados/organização & administração , Humanos , Espectrometria de Massas em Tandem/normas , Estudos de Validação como AssuntoRESUMO
It is commonly acknowledged that random and systematic analytical errors contribute to poor data quality, and moreover, to imprecise and inaccurate pharmacokinetic parameters. To investigate the random errors in GLP bioanalysis, common ground has been found in today's bioanalysis to assess the reproducibility of the method by reanalyzing part of the incurred samples. The undesired systematic errors in bioanalysis affecting the trueness of the method and leading to inaccurate data remain relatively unattended so far. In order to obtain both precise and accurate data it is suggested in this paper to apply standard addition experiments to calculate the relative systematic errors as an estimate for the incurred sample accuracy. This approach, which can be seen as an important extension to current guidelines in GLP bioanalysis, is illustrated by assessing the accuracy of the bioanalytical results for a bioequivalence study for alendronate.