Conexiant
Login
  • The Analytical Scientist
  • The Cannabis Scientist
  • The Medicine Maker
  • The Ophthalmologist
  • The Pathologist
  • The Traditional Scientist
The Analytical Scientist
  • Explore

    Explore

    • Latest
    • News & Research
    • Trends & Challenges
    • Keynote Interviews
    • Opinion & Personal Narratives
    • Product Profiles
    • App Notes

    Featured Topics

    • Mass Spectrometry
    • Chromatography
    • Spectroscopy

    Issues

    • Latest Issue
    • Archive
  • Topics

    Techniques & Tools

    • Mass Spectrometry
    • Chromatography
    • Spectroscopy
    • Microscopy
    • Sensors
    • Data and AI

    • View All Topics

    Applications & Fields

    • Clinical
    • Environmental
    • Food, Beverage & Agriculture
    • Pharma and Biopharma
    • Omics
    • Forensics
  • People & Profiles

    People & Profiles

    • Power List
    • Voices in the Community
    • Sitting Down With
    • Authors & Contributors
  • Business & Education

    Business & Education

    • Innovation
    • Business & Entrepreneurship
    • Career Pathways
  • Events
    • Live Events
    • Webinars
  • Multimedia
    • Video
Subscribe
Subscribe

False

The Analytical Scientist / App Notes / 2019 / Particle Size Measurement for Small Quantities of Dry Powders

Particle Size Measurement for Small Quantities of Dry Powders

06/11/2019

Share

Featured Image

The routine measurement of particle size plays an important role in pharmaceutical and other industries, where it is often a critical-to-quality attribute for the product. Dispersion is critical for any particle size measurement and two principle routes are available in laser diffraction systems, wet and dry. If the powder is processed in a dry state and the end product is a dry powder, then a dry dispersion method is generally preferred. In the case of the pharmaceutical industry, active ingredients and excipients are generally handled dry during processing, and may be a dry powder in the final form for example in dry powder inhalers. In the early stages of product development, a pharmaceutical manufacturer may wish to measure the particle size of a sample of dry powder with less than 100mg of material in existence.

In this application note, we measure aliquots as small as 5mg of fine grade, pharmaceutical lactose and show that the measurement reproducibility is well within the ISO laser diffraction standard [1] guidelines on repeatability. This fine grade of lactose was chosen as both an established model material for active pharmaceutical ingredients and as a highly cohesive powder that is difficult to disperse.

Measuring a fine grade of lactose

Aliquots of lactose were weighed out and handled with care to avoid powder compaction or adhesion to the weigh boat. An aliquot of 5mg was chosen as this allows for 20 measurements from the available 100mg, providing sufficient aliquots for both method development and reproducibility testing.

Reproducibility in 5mg aliquots

Six aliquots of the fine grade lactose were prepared and dispersed using the Aero S. A typical particle size distribution is shown in figure 1. The variation in the results, or reproducibility, was less than 0.8% for Dv (50) (table 1A). The ISO standard [1] states that the variation between repeated measurements (RSD %) should be less than 3% for Dv (50). As fine lactose is a particularly cohesive material achieving such low variation between measurements illustrates the excellent dispersion performance of the Aero S.

Download the full Application Note as PDF

Newsletters

Receive the latest analytical scientist news, personalities, education, and career development – weekly to your inbox.

Newsletter Signup Image

Explore More in Analytical Science

Dive deeper into the analytical science. Explore the latest articles, case studies, expert insights, and groundbreaking research.

False

Advertisement

Recommended

False

Related Content

Ionic impurities in drug products – USP proposes new ion chromatography method
Ionic impurities in drug products – USP proposes new ion chromatography method

January 21, 2019

Chloride and sulfate are common impurities present in drug substances and drug products...

Decoding Dangerous Drinks with a Spectral Sensor
Decoding Dangerous Drinks with a Spectral Sensor

January 24, 2019

Have you ever heard that moonshine will make you go blind? Today, even your favorite, top-shelf liquor may be just as much of a risk...

Volume Fraction Determination of Ethanol in Splash-Blended Fuel Mixture
Volume Fraction Determination of Ethanol in Splash-Blended Fuel Mixture

January 24, 2019

While electric vehicles are becoming more mainstream the use of traditional gasoline engines will have a place in society for decades to come...

Cleaning Up IPA Production with Stage-by-Stage MIR Analysis
Cleaning Up IPA Production with Stage-by-Stage MIR Analysis

January 24, 2019

2-Propanol is one of the most common solvents in the world, with over 2 million tons produced in 2003 (Science)...

False

The Analytical Scientist
Subscribe

About

  • About Us
  • Work at Conexiant Europe
  • Terms and Conditions
  • Privacy Policy
  • Advertise With Us
  • Contact Us

Copyright © 2025 Texere Publishing Limited (trading as Conexiant), with registered number 08113419 whose registered office is at Booths No. 1, Booths Park, Chelford Road, Knutsford, England, WA16 8GS.