Mastering particle size analysis: lessons, challenges, and future directions from the FDA-CRCG workshop

Area of Science:

• Pharmaceutical Sciences
• Analytical Chemistry
• Materials Science

Background:

• Particle-size distribution (PSD) is critical for drug formulation, stability, and performance.
• Existing methods for PSD measurement present significant scientific and practical complexities.
• Standardized practices are needed to ensure reliable and comparable PSD data in pharmaceutical development.

Purpose of the Study:

• To foster a shared understanding of PSD measurement principles and best practices.
• To address the complexities in interpreting PSD data from different techniques.
• To promote robust analytical procedures and data integrity in pharmaceutical quality assessment.

Main Methods:

• A hybrid workshop co-hosted by the FDA and CRCG focused on Dynamic Light Scattering (DLS) and Laser Diffraction (LD).
• Integrated scientific lectures, vendor demonstrations, and case-study discussions.
• Pre-workshop characterization of diverse materials by participating vendors established a baseline.

Main Results:

• Discussions emphasized that PSD data interpretation is context-dependent (model, sample, purpose).
• Methodological transparency was deemed more important than pursuing a single 'true' particle size.
• Key outcomes included identifying sources of inter-laboratory variability and agreeing on harmonized terminology and reporting.

Conclusions:

• Reliable PSD characterization necessitates 'fit-for-purpose' analytical design and transparent reporting.
• Improved comparability of PSD data across techniques and laboratories is essential for regulatory confidence.
• Commitments were made to develop a community white paper and conduct an inter-laboratory study.