Spray drying process challenges and considerations for inhaled biologics

Spray drying presents numerous advantages over other drying technologies, particularly for inhaled biologics because of the fine-tuned particle attributes requirements. To fully leverage these benefits, it is crucial to address several process challenges and considerations throughout the end-to-end spray-drying process, including stages prior to, during, and post- drying. This review provides a detailed overview of the challenges associated with spray-drying of biologics along with the aspects of protein degradation. Furthermore, it delineates the entire spray-drying process, comprising feed solution preparation, spray drying, and bulk powder handling, along with protein degradation mechanisms and analytical tools for protein and aerosol performance assessment. Pertaining to inhaled biologic products, this review also sheds light on major bottlenecks and potential challenges, particularly during scale-up. While some challenges are yet to be conclusively addressed, potential control and mitigation strategies from industry perspective are presented and examined. Lastly, the review briefly explores trending topics in this field that could add value to the standard spray-drying process and may be incorporated in future drying technologies.