Formulation of Neulasta (pegfilgrastim).

Neulasta (pegfilgrastim) is a PEGylated version of its parent molecule NEUPOGEN (Filgrastim). This work describes the formulation development for Neulasta (pegfilgrastim), and the analytical techniques used to monitor degradation during these studies. Stability was assessed as a function of pH, protein concentration, buffer type, tonicity modifiers and surfactant concentration under both accelerated conditions and quiescent long-term storage. The stability of Neulasta (pegfilgrastim) to agitation and successive freeze-thaw cycles was also assessed. Neulasta (pegfilgrastim), at a protein concentration of 10 mg/mL formulated in 10 mM acetate, pH 4.0 with 5% sorbitol and 0.004% polysorbate 20, is stable for two years stored at 2-8 degrees C.