Assessment of the stability of dalteparin sodium in prepared syringes for up to thirty days: An in vitro study

Background: If a low-molecular-weight heparin (LMWH) injectable formulation maintains its stability for up to 30 days, substantial cost reductions in hospital stay could be achieved with its use on an outpatient basis in patients who might otherwise be treated with IV heparin as inpatients. Objective: This study was designed to assess the stability for up to 30 days of injectable solutions of the LMWH dalteparin sodium when repackaged in plastic syringes. Methods: In the first part of the study, 1-mL and 3-mL plastic syringes were filled with the contents of a 10,000-IU/mL dalteparin ampule or a 25,000-IU/mL dalteparin multidose vial. In a separate part of the study, 1-mL and 3-mL syringes were filled with doses of 7500 IU and 10,000 IU, respectively, from a 10,000-IU/mL multidose vial. After the syringes were brought to room temperature or 4°C, the stability of dalteparin was assessed over 30 days by measuring anti-factor Xa levels. Results: No significant loss of dalteparin activity was found for up to 30 days in the syringes after storage at room temperature or 4°C. The solutions retained anti-factor Xa activity at room temperature and under refrigeration. Conclusion: Dalteparin is stable for up to 30 days when stored at room temperature or 4°C. The findings suggest that preparation of a postdischarge supply of dalteparin is feasible, contributing to more convenient and effective management of outpatients at risk for thrombotic complications.