Data/hora: 01/06/2024 00:49:31

Provedor de dados: | 56
País: | Brazil
Título: | Biological evaluation of recombinant human erythropoietin in pharmaceutical products
Autores: | Ramos,A.S.; Schmidt,C.A.; Andrade,S.S.; Fronza,M.; Rafferty,B.; Dalmora,S.L.
Data: | 2003-11-01
Ano: | 2003
Palavras-chave: | Recombinant human erythropoietin; Bioassay; Polycythemia; Reticulocyte counting; Normocythemic mice.
Resumo: | The potencies of mammalian cell-derived recombinant human erythropoietin pharmaceutical preparations, from a total of five manufacturers, were assessed by in vivo bioassay using standardized protocols. Eight-week-old normocythemic mice received a single subcutaneous injection followed by blood sampling 96 h later or multiple daily injections with blood sampling 24 h after the last injection. Reticulocyte counting by microscopic examination was employed as the end-point using the brilliant cresyl blue or selective hemolysis methods, together with automated flow cytometry. Different injection schedules were investigated and dose-response curves for the European Pharmacopoeia Biological Reference Preparation of erythropoietin were compared. Manual and automated methods of reticulocyte counting were correlated with respect to assay validity and precision. Using 8 mice per treatment group, intra-assay precision determined for all of the assays in the study showed coefficients of variation of 12.1-28.4% for the brilliant cresyl blue method, 14.1-30.8% for the selective hemolysis method and 8.5-19.7% for the flow cytometry method. Applying the single injection protocol, a combination of at least two independent assays was required to achieve the precision potency and confidence limits indicated by the manufacturers, while the multiple daily injection protocol yielded the same acceptable results within a single assay. Although the latter protocol using flow cytometry for reticulocyte counting gave more precise and reproducible results (intra-assay coefficients of variation: 5.9-14.2%), the well-characterized manual methods provide equally valid alternatives for the quality control of recombinant human erythropoietin therapeutic products.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001100014
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2003001100014
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.36 n.11 2003
Fonte: | info:eu-repo/semantics/openAccess