A Guide to D-values in Pharmaceutical Particle Characterisation
In the manufacturing of powders, pellets, granules, etc. particle size and the particle size distribution (PSD) of materials play a key role in the processing of the product and ultimately the quality of the finished product. The analysis of particles and characterisation of their size and shape are therefore of great importance in pharma, among other industries. This paper explains how pharma uses D-values for measuring PSD.
The most widely used method of describing particle size distributions are D values. The D10, D50 and D90 are commonly used to represent the midpoint and range of the particle sizes of a given sample. Particle size distributions have been traditionally calculated based on sieve analysis results, creating an S-curve of cumulative mass retained against sieve mesh size, and calculating the intercepts for 10%, 50% and 90% mass. A new approach is required to calculate particle size distributions from laser and imaging technologies however, as these methods do not measure the mass of particles.
For a guide to particle sizing techniques and definitions used within the pharmaceutical industry, download the whitepaper.