Particle characterisation, such as particle size, is of immense importance for all solid pharmaceutical products, both in relation to processability and bioavailability. Unfortunately, particle size is not always easily controlled during manufacturing and even slight changes in manufacturing conditions might lead to quite large size changes. Furthermore, a change in API supplier almost certainly leads to new particle characteristics. In all cases where a risk of change in particle size exists, it should be evaluated whether the changes will affect the drug properties – and if the method used for characterisation of the particles is still valid.
By Thomas Andresen, QA Manager, Soren Lund Kristensen, CEO, and Karin Liltorp, Principal Scientist, Flow Sciences