Stability of Filgrastim and Epoetin Alfa in a System Designed for Enteral Administration in Neonates

Abstract

OBJECTIVE: To determine the stability of recombinant granulocyte colony—stimulating factor (rG-CSF, filgrastim) and recombinant erythropoietin (rEpo, epoetin alfa) in a solution designed for enteral administration in the neonatal intensive care unit. DESIGN: Filgrastim and epoetin alfa were added to a solution with NaCl 0.9%, sodium acetate, potassium chloride, and human albumin in concentrations designed to mimic human amniotic fluid. Additionally, the solution was dripped through polyvinyl chloride feeding tubes to simulate feedings, and aliquots were collected before, during, and after priming of the tube. Other aliquots were either frozen immediately, stored at room temperature, or refrigerated for 0, 6, 12, 18, and 24 hours. MAIN OUTCOME MEASURES: Filgrastim and epoetin alfa concentrations in the various aliquots were compared with the concentrations in the original solution. RESULTS: Filgrastim and epoetin alfa concentrations were stable for at least 24 hours when refrigerated and for at least three weeks when frozen. At room temperature, filgrastim was stable for 18 hours and epoetin alfa for 24 hours. Filgrastim concentrations did not vary significantly before, during, or after priming of the feeding tube, whereas epoetin alfa concentrations decreased significantly unless the feeding tube was primed with 10 mL of solution. CONCLUSIONS: Filgrastim and epoetin alfa were stable in our amniotic fluid—like solution. In this respect, our solution is suitable for enteral administration to patients in the neonatal intensive care unit.