Potency evaluation of recombinant human erythropoietin in Tunisia using normocythaemic mice bioassay

The potency of a recombinant human erythropoietin (rhEPO) pharmaceutical preparation was evaluated by the normocythaemic mice bioassay using standardized and randomized protocol of European Pharmacopeia 5.0. Eight-week-old normocythaemic B6D2F1/c mice received single daily injections of test solutions (EPOTIN recombinant human erythropoietin, batch preparation) at different concentrations. Erythropoietin biological reference product (batch 3.3) was used as standard. The suitability of the bioassay was recorded according to gender and age. The blood sampling was performed 4 days after the last injection and reticulocytes were counted by manual and automated methods. Intra-assay precision was analyzed and Bland-Altman plot was obtained. The effect of rhEPO administration doses on the hemoglobin concentration, hematocrit and number of red blood cells in the blood stream were investigated. The dose response curve was linear in the concentration range of 20-80 IU/ml. The relative potency was estimated to 13.78 and 71.53% of the stated potency, for male and female mice, respectively. The recorded limits were compared to the required ones. This study gives valuable insights for better control of biosimilars and bioproducts.