Understanding effect of filtration and washing on dried product: paracetamol case study

One of the key challenges that the pharmaceutical industry is trying to address is to maintain particle properties across the entire purification and isolation process.

This research focuses on the effect of slurry properties, wash solvent, filtration and washing mechanisms on API agglomeration/granulation during the processes of downstream isolation and the impact on the physical properties of the product. In this investigation, each isolation step was analysed to identify factors that have the potential to affect the final product qualities using a multivariate statistical design of experiments approach.
The factors which were most detrimental in increasing particle agglomeration, were found to be the particle size of the input material, the quantity and identity of wash solvent and the drying mode. Low boiling point aliphatic hydrocarbons are shown to be desirable final wash solvents to reduce the extent and strength of agglomerates and to produce free flowing powder/readily disrupted agglomerates.