(553e) Development And Scale-Up Of Efficient Api Drying Using Fluid Bed Dryer

The API wet cake, isolated from a mixture of water, ethanol, and small percentage of heptanes and other solvents, has a LOD approximately 50% and is dried with an agitated drier under vacuum and heat. The dried API from the agitated drier in production typically produces small ?ball? shaped materials, which makes the drying operation less efficient and takes over 2 days to dry a batch. The demand for the API has increased significantly in recent years, thus, additional drying capacity and alternative drying technology is required to meet the increased demand. This led us to investigate an alternative and more efficient drying technology to dry the wet cake, and to seek an alternative milling technique to consistently produce the desired particle size. Fluid bed dryer (FBD) was chosen because it allows for faster drying and produces a consistent pre-milled particle size distribution.

We will present the detailed development and scale-up of FBD drying technology to dry the API wet cake, from lab scale to pilot scale and finally to production scale. Many obstacles have been overcome successfully, such as potential degradation of API by hot FBD air, flowability of wet cake for delumping and automatic feeding, efficient removal of residual heptanes to minimize environmental emissions, and handling of the hygroscopic dry API. The outcome of this project is that an efficient drying procedure using fluid bed dryer has been developed and scaled-up successfully to commercial production with a dramatic reduction of drying cycle time (to approximately 3 hours per FBD cart), producing a consistent particle size distribution with desired physical properties and minimum environmental emission. The efficient removal of heptanes prior to FBD drying will be also discussed. This work significantly increases the throughput of API drying in commercial production.