Drying Working group

The drying of pharmaceutical substances involves a complex interaction between the material properties of the substances and the environments in which they are processed.  The relations controlling the response of particular materials within current industrial equipment (e.g. agitated dryers) are not fully understood and predicting and controlling the impact on API quality attributes is difficult.  There are currently several gaps in equipment technology, experimental and computational modeling, and a unified guidance, that if addressed, would help improve the predictability of API quality attributes throughout the drying process.

The impact of the agitated drying process on API quality attributes is a complex process.  Although the intention of the drying process is to remove excess solvent from the wet cake, API particle size can be impacted by particle attrition and the crystalline form can change by desolvation/dehydration of solvates/hydrates or the application of mechanical stress.  The drying agitation protocol can also impact the formation of agglomerates depending on the solvent level (LOD) in the cake upon initiating agitation.  Although drying is a commonly utilized unit operation in the pharmaceutical industry, the various workflows and practices in the industry have not been coordinated to form a foundation for providing an overall guidance.   

The aims and scope of this working group are focused on improving upon the knowledge and best practices of drying pharmaceutical drug substances with agitated dryers.  Members focus on common drying interests.  The range of activities includes experience sharing, developing scale-down drying equipment, modeling of drying kinetics and physical property control, and evaluating materials characterization approaches as monitored by PAT or offline samples.