Screening of formulation parameters for stabilizing recombinant human serum albumin (rHSA) in liquid formulations

In the present study, the stabilizing effect of excipients present in recombinant Human Serum Albumin (rHSA) solutions are studied using rheological analysis. The study was conducted using Design of Experiment (DoE) principles and multivariate analysis approach. It is observed that the excipients octanoate and polysorbate 80 used in the Recombumin Alpha® formulation both increase the stability of the protein reflected by an observed decrease in the complex viscosity interpreted as a decreasing degree of self-association. Octanoate seems to be efficient in protecting the protein at higher temperatures, whereas polysorbate protects against self-association at lower temperatures. Additionally, a synergistic effect of octanoate and polysorbate 80 was observed in a non-linear fashion. This effect would be difficult to assess in a study using univariate analysis of these complex formulations, however the multivariate approach using DoE and Principal Component Analysis (PCA) efficiently illustrated its usefulness in the current study.