Use of biophysical characterization in preformulation development of a heavy-chain fragment of botulinum serotype B: evaluation of suitable purification process conditions.

Purpose: The purpose of this study was to investigate the physicochemical and structural characteristics of recombinant botulinum serotype B (rBoNTB(Hc)) under various conditions and to use the information in evaluating suitable purification process conditions.

Methods: The solubility of rBoNTB(Hc) was evaluated at pH 4, 5, 6 7.5, 8, and 9.