Short-term stability of a new generic sodium ferric gluconate in complex with sucrose

Sodium ferric gluconate in complex (SFG) is used to treat iron deficiency anemia in patients aged ≥6 years undergoing chronic hemodialysis and receiving supplemental epoetin therapy. Both the branded product (Ferrlecit, branded SFG) and a new generic version of sodium ferric gluconate in complex (Nulecit; generic SFG) are provided in 5 mL vials. SFG may be administered by slow intravenous (IV) injection of the undiluted product or by 1 h IV infusion after dilution in 100 mL 0.9% sodium chloride. This study evaluated the short-term stability of undiluted and diluted generic SFG at room temperature and under refrigeration.

Samples of generic SFG undiluted in 10 mL syringes or diluted in IV infusion bags containing 0.9% sodium chloride solution were stored at room temperature or under refrigerated conditions (2-8°C). Samples at room temperature were stored for ≤48 h if undiluted and for ≤24 h if diluted. All refrigerated samples were stored for ≤7 days. Parameters evaluated were elemental iron (Fe) concentration and SFG apparent molecular weight. All tests were performed on two lots of the generic product.

Fe concentrations were identical in both lots and did not vary substantially over time under different conditions of storage or dilution. SFG apparent molecular weight varied across all samples from 306,000 to 354,000 Daltons, well within the range of 289,000 to 440,000 Daltons specified as the molecular weight in the FDA-approved prescribing information.

Iron content and SFG apparent molecular weight were stable under all experimental conditions. Undiluted generic SFG was stable for ≥2 days at room temperature and ≥7 days under refrigerated conditions, and generic SFG diluted in IV infusion bags containing 0.9% sodium chloride solution was stable for ≥1 day at room temperature and ≥7 days under refrigerated conditions.