Recombinant human granulocyte colony stimulating factor pre-screening and screening of stabilizing carbohydrates and polyols

Protein stabilization by solvent additives is frequently used concept in formulation development, although new technologies implemented over the past decade can improve protein biophysical as well as clinical properties by protein structural design (e.g. PEGylation, acylation, hesylation). The scope of this work was to evaluate the effect of chosen carbohydrate or polyol stabilizer in the formulation; firstly on linear peptide sequences on instable model of rHuG-CSF cleaved macromolecule by novel method named protein and peptide stabilizer pre-screening PPSP (formulated tryptic digest mixture stability evaluation in 54 h) and on overall stability of rHuG-CSF macromolecule by quantifying all relevant degradation parameters. Comprehensive protein stabilizing screening study included conformational analysis of formulated rHuG-CSF protein to obtain information on its secondary structure conformational stability. Protein aggregation induced by modulating conditions in solution (e.g. thermal stress and agitation) was monitored over discrete time periods. Oxidation and deamidation, as well as truncation or hydrolysis were accurately quantified. Together with pre-screening data, obtained by fast and resourceful amino acid sequence degradation analysis by LC–MS, statistical data evaluation of stabilizing contribution of substances selected from group of carbohydrates and polyols was performed. According to the statistical interpretation of obtained results the stabilizers were ranked in the following order: turanose, d-trehalose, lactitol, acetate buffer (non-stabilized sample), xylitol, cellobiitol, sorbitol, d-lyxose, leucrose, sorbitol without polysorbate, cellobiose.