Drying technologies for biopharmaceutical applications: Recent developments and future direction

Drying is a commonly used processing technique for the manufacture of biotherapeutic products. Removal of water provides numerous benefits, including ease of handling and storage, reduction in transportation costs, and improved stability, to name a few. Typically, drying is accomplished through freeze-drying, as evidenced by the availability of several lyophilized products on the market. There are, however, several drawbacks to lyophilization, including the lengthy process time required for drying, low energy efficiency, and the high cost of purchasing and maintaining the equipment. Furthermore, lyophilization is a batch process and may be challenging to adapt and implement within a continuous manufacturing process scheme. These limitations have led to the search for next-generation drying technologies that can be applied to the manufacture of biotherapeutic products. Several alternative drying methods are reviewed herein with particular emphasis on the advantages and disadvantages of each technology in comparison to lyophilization and the potential of each to be utilized for drying biotherapeutic compounds.