Biotechnology-derived erythropoietin is a sialoglycoprotein, which stimulates erythropoiesis, and it is clinically used for the treatment of anaemia related to chronic renal failure. N-Acetylneuraminic acid content was quantified by a reversed-phase liquid chromatography method with fluorescence detection giving values higher than 108.74 ng mg À1 . An alternative in vitro TF-1 cell proliferation bioassay was studied showing a lower mean difference of the estimated potency of 2.67%, compared to the normocythaemic mice bioassay, with non-significant differences (p > 0.05). Biopharmaceutical products were also analyzed by validated reversed-phase and size-exclusion liquid chromatography methods and compared to the in vivo bioassay, showing lower mean differences of the content/potencies of 2.11 and 1.21%, respectively. Higher molecular mass forms and deamidated/sulphoxide forms showed mean bioactivities reduced to about 10%, for both. The TF-1 cell culture assay in conjunction with the determination of sialic acids represents an advance that can be correlated with the normocythaemic mice bioassay and the physicochemical methods, allowing for the establishment of alternative methods, which can be applied to monitor the stability, quality control, and thereby ensuring the therapeutic efficacy of the biological medicine.

Unfractionated heparins are used clinically as anticoagulants. The biological potency of thirteen samples of raw material and pharmaceutical formulations were assessed utilizing the 5th International Standard of heparin using the sheep plasma coagulation inhibition assay, activated partial thromboplastin time, anti-factor Xa assay, and anti-factor IIa assay, resulting in mean potencies of 101.15%, 96.15%, 98.15% and 99.37%, respectively. The samples were also evaluated by the protamine neutralization test giving results within the range of 92-138 IU/mg. The anti-factor IIa assay was performed showing reproducibility and significant correlation with the pharmacopoeial assays, thus demonstrating it to be a feasible alternative to the sheep plasma coagulation inhibition assay. Moreover, an analysis by nuclear magnetic resonance and capillary electrophoresis showed some peaks attributable to oversulfated chondroitin sulfate. The results show that batch-to-batch variations and the quality of samples contributed to improvements in the quality control of pharmaceutical products and to assure the safe use and clinical efficacy of this biological medicine. Rev. Bras. Hematol. Hemoter.

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