Described herein is a composition and process for synthesizing a human serum albumin (HSA) based plasma replacement composition that includes a polymerized HSA (PolyHSA) that is chemically stabilized by the reduction of Schiff bases. The PolyHSA may have a molecular weight of at least about 100 kDa and may optionally have a cross-linker to HSA molar ratio of at least about 10:1. The PolyHSA composition is useful for restoring a subjects circulatory volume.
