A routine determination of particle sizes of a product that we have analysed for the last 8 years suddenly showed a new distribution – and even though the specifications were still met, it was relevant to investigate this issue further.
The customer was very puzzled: Were we absolutely sure that we had not changed something in the experimental procedure? – because they had definitely not!
We carefully reviewed the experimental procedure and the customer had a closer look at the processing procedure. We did not find any reasons for the new distribution. At the end the customer found out that something had actually changed during production: One of the tubes in the production line had been changed – a change that they were absolutely sure would not affect the outcome!
Sometimes minimal disturbance of the crystallization conditions might cause large changes in particle sizes – and for the same reason, Regulatory Authorities require verification of the particle size distribution when something in the production line is changed.
Below: A SEM picture of agglomeration of particles
