High-Throughput Screening for Colloidal Stability of Peptide Formulations Using Dynamic and Static Light Scattering.

Area of Science:

• Pharmaceutical Development
• Biophysical Chemistry
• Drug Formulation

Background:

• Stabilizing therapeutic proteins against aggregation is critical in drug product development.
• Quantifying peptide aggregates is challenging due to their small molecular size.
• High-throughput (HT) screening methods are needed for efficient formulation development.

Purpose of the Study:

• Investigate diffusion self-interaction parameters (kD) and osmotic second virial coefficients (B22) for HT screening of peptide formulations.
• Compare these parameters to thermal stress effects on colloidal stability.
• Identify optimal formulation conditions for minimizing peptide aggregation risk.

Main Methods:

• Utilized a formulation matrix with six buffering systems (two pH values), four tonicity agents, and a preservative.
• Assessed colloidal stability using diffusion self-interaction parameters (kD) and osmotic second virial coefficients (B22).
• Compared HT screening parameters with thermal stress-induced aggregation.

Main Results:

• Electrostatic interactions were identified as the primary drivers of colloidal stability.
• Optimal formulations included acetate/succinate buffers (pH 4.5) with glycerol/mannitol and m-cresol.
• Diffusion self-interaction (kD) parameters effectively predicted colloidal stability for peptides, similar to globular proteins and antibodies.

Conclusions:

• Diffusion self-interaction (kD) parameters serve as a reliable surrogate for B22 in high-throughput screening of peptide formulations.
• Formulation assessment based solely on kD provides valuable insights for optimizing colloidal stability in early peptide drug development.
• This approach requires a limited peptide amount (approx. 360 mg).