Submicron Protein Particle Characterization using Resistive Pulse Sensing and Conventional Light Scattering Based...

Area of Science:

• Biopharmaceutical analysis
• Nanoparticle characterization
• Protein formulation science

Background:

• Characterizing submicron protein particles (0.1-1μm) is difficult due to limitations in current instrumentation.
• Monitoring particle size and concentration across a broad range presents significant analytical challenges in biopharmaceutical development.

Purpose of the Study:

• To report for the first time the characterization of submicron protein particles using resistive pulse sensing (RPS).
• To establish a method for monitoring submicron protein particles in pharmaceutical formulations.

Main Methods:

• Resistive pulse sensing (RPS) was employed alongside dynamic light scattering (DLS) and size-exclusion chromatography with multi-angle light scattering (SEC-MALS).
• Analyses were conducted on protein and placebo formulations, size standards, and stressed protein samples.

Main Results:

• A robust RPS method was developed, suitable for particle concentrations ranging from 4 × 10⁷ to 1 × 10¹¹ particles/mL.
• RPS particle size distributions demonstrated high resolution and consistency with DLS and SEC-MALS data.
• RPS provided accurate particle counts and superior size resolution compared to light scattering techniques.

Conclusions:

• Resistive pulse sensing is a viable technique for characterizing highly polydisperse submicron particles in protein formulations.
• RPS-derived particle distribution data offer critical insights into particle formation mechanisms under various stress conditions relevant to biologics development.