Recombinant Albumin: Characterization As A Pharmaceutical Excipient In The Stabilization Of Therapeutic Protein Products

By Phuong Tran and Yanling Lu

Recombumin®, a recombinant human albumin expressed in Saccharomyces cerevisiae, has recently been investigated for its ability to protect therapeutic proteins against degradation, in particular addressing surface adsorption, oxidation and aggregation. APIs, including transforming growth factor-ß3 (TGF-ß3), insulin-like growth factor-I (IGF-I), IgG1 antibody and a malarial antigen vaccine protein were formulated in the presence of Recombumin and the effect on stability was examined. These studies established that Recombumin provided complete protection of TGF-ß3 against product losses due to nonspecific adsorption to test container surfaces. In addition, Recombumin has been shown to act as an antioxidant in protecting IGF-I against oxidation by reactive oxygen species. Furthermore, Recombumin was also shown to significantly reduce aggregate formation as seen in both IgG1 antibody and a malarial antigen protein. In all three case models, excipients commonly used for the purpose of formulating protein drugs were also examined and the results indicated that Recombumin performed as well as and often better than the comparators. The following data demonstrate that Recombumin as an excipient has the capacity to improve: (1) physical stability, including protection against surface adsorption and aggregation; (2) chemical stability, in preventing oxidation.