Research on Particle Size Measurement of Lactose Using a Laser Particle Size Analyser

Why Particle Size Matters in Lactose Analysis

Lactose is one of the most widely used excipients in tablet manufacturing. Its particle size distribution can influence important powder properties, including flowability, mixing behaviour and compression performance. Accurate particle size measurement helps pharmaceutical manufacturers understand the characteristics of their raw materials and maintain consistent production quality.

Laser diffraction provides a reliable method for measuring particle size distribution. However, researchers must select suitable measurement conditions to obtain meaningful results, particularly when they analyse powders with different physical properties.

Understanding USP and ISO 13320 Requirements

The United States Pharmacopeia (USP) provides guidance on measuring the particle size of raw materials using laser diffraction. This guidance covers the instrument’s structure and operating principles, wet and dry dispersion methods, and factors that can influence measurement results. The international standard ISO 13320 also outlines requirements and recommendations for particle size analysis using laser diffraction.

Although these guidelines establish a framework for reliable measurement, researchers still need to determine the most appropriate settings for individual materials. For lactose, selecting the correct dry dispersion pressure and evaluating the differences between wet and dry measurements present particular challenges.

Comparing Wet and Dry Dispersion Methods

Dry dispersion uses compressed air to separate particles before measurement, while wet dispersion suspends particles in a suitable liquid. Both methods can provide useful particle size distribution data, but the selected conditions can affect the results.

Excessive dry dispersion pressure may break fragile particles or alter the measured distribution, while insufficient pressure may leave particles agglomerated. Wet dispersion also requires careful selection of the dispersant and preparation conditions to achieve representative results.

Improving Lactose Particle Size Measurement

This application note investigates lactose particle size distribution using a systematic approach that follows the principles outlined in the USP and ISO 13320. The research examines dispersion conditions and evaluates the results obtained using wet and dry methods.

By exploring these factors, the study helps researchers establish suitable measurement procedures, improve result consistency and make informed decisions when characterising lactose for pharmaceutical applications. Reliable particle size data supports raw material assessment, formulation development and routine quality control.