Teva api’s PSD measurement techniques and best practices

This article was updated 22.3.2022

Teva api’s PSD measurement techniques deliver customer benefits

PSD method development validation and analysis

Active Pharmaceutical Ingredients have several important physical properties including polymorphism, water content, density and particle size. Particle Size Distribution, or PSD, has a direct influence on material properties such as: flowability, handling, dissolution rate, stability, and efficacy of delivery.

Our webinar, The Perfect Particle — Why Size Matters, was a deep-dive into the world of particle size. Particle size is one of the first physical properties that needs to be considered in an active pharmaceutical ingredient (API).

During the webinar, Zohar De-Valenca, our Senior Manager of Manufacturing Sciences & Technology, spoke to our listeners about why particle size is so crucial and what top technologies exist for the milling of APIs. Enrico Bettitini, Subject Matter Expert in Solid State, then answered questions from the audience.


PSD is one of the most important physical properties of powder APIs. To ensure robust formulation, it is essential that PSD measurement be accurate, repetitive and consistent. Teva api uses industry-leading best practices for PSD method development, such as microscopy and laser diffraction, to support more than 400 APIs and Help us to meet each customer’s unique needs and specifications.

Examples for suggested solutions in case the results are not the same as your API supplier:

Case: Using different PSD methods – Teva api PSD method is by wet dispersion of the API and customer’s by dry dispersion.

  • Impact: In most cases the customer will get much lower results than our CoA, sometimes OOS.
  • Solutions: one of the sides adopting the other’s method OR Teva api will develop and use a third method that will obtain similar results like the customer’s.

Case: Using the same PSD method with slight differences in measurement protocol or equipment – Both Teva api and customer methods are by wet dispersion of API but one of the methods is more aggressive.

  • Impact: In many cases the customer will get different results than our CoA, sometimes OOS.
  • Solution: aligning the method / sample preparation aggressiveness/gentleness like in customer’s method at Teva api QC in order to obtain similar results like the customer’s.

Teva api recommends our customers make use of Teva api’s years of experience and adopt our improved PSD measurement methods to help to ensure accurate and compliant results. This short video shares the practices and processes we recommend, advises on the important customer benefits offered by Teva api, and shows some of the state-of-the-art tools and techniques we use to deliver precise PSD characterizations and comprehensive analysis for each API.

Please feel free to contact us with any questions, or if you need Teva api’s support with PSD related information for your API related projects