title: Effects of ionic strength and sugars on the aggregation propensity of monoclonal antibodies: influence of colloidal and conformational stabilities.
abstract: OBJECTIVE
  To develop a general strategy for optimizing monoclonal antibody (MAb) formulations.
  
  
  METHODS
  Colloidal stabilities of four representative MAbs solutions were assessed based on the second virial coefficient (B 2) at 20°C and 40°C, and net charges at different NaCl concentrations, and/or in the presence of sugars. Conformational stabilities were evaluated from the unfolding temperatures. The aggregation propensities were determined at 40°C and after freeze-thawing. The electrostatic potential of antibody surfaces was simulated for the development of rational formulations.
  
  
  RESULTS
  Similar B 2 values were obtained at 20°C and 40°C, implying little dependence on temperature. B 2 correlated quantitatively with aggregation propensities at 40°C. The net charge partly correlated with colloidal stability. Salts stabilized or destabilized MAbs, depending on repulsive or attractive interactions. Sugars improved the aggregation propensity under freeze-thaw stress through improved conformational stability. Uneven and even distributions of potential surfaces were attributed to attractive and strong repulsive electrostatic interactions.
  
  
  CONCLUSIONS
  Assessment of colloidal stability at the lowest ionic strength is particularly effective for the development of formulations. If necessary, salts are added to enhance the colloidal stability. Sugars further improved aggregation propensities by enhancing conformational stability. These behaviors are rationally predictable according to the surface potentials of MAbs.
authors: Analytical & Quality Evaluation Research Laboratories, Daiichi Sankyo Co., Ltd., 1-12-1, Shinomiya, Hiratsuka-shi, Kanagawa, 254-0014, Japan.
authors: Shuntaro
authors: S
authors: Saito
authors: Jun
authors: J
authors: Hasegawa
authors: Naoki
authors: N
authors: Kobayashi
authors: Toshiaki
authors: T
authors: Tomitsuka
authors: Susumu
authors: S
authors: Uchiyama
authors: Kiichi
authors: K
authors: Fukui
mesh_terms: D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000737:chemistry*; D002241:Carbohydrates / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry; D005079:Excipients / Q000737:chemistry*; D005615:Freezing; D006801:Humans; D008958:Models, Molecular; D009994:Osmolar Concentration; D011487:Protein Conformation; D055550:Protein Stability; D012965:Sodium Chloride / Q000737:chemistry
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D002241:Carbohydrates; D003102:Colloids; D005079:Excipients; D012965:Sodium Chloride