By Kevin Queensen , Natoli Engineering
Difficulty moving a formulation from an R&D tablet press to a production press is not an uncommon issue for tablet manufacturers. Developing a robust solid dose formulation that you can scale up for commercial production without encountering tableting issues is an ongoing challenge for any company that makes tablets, whether pharmaceutical, nutraceutical, veterinary, or industrial.
During the R&D process, scientists typically use a small-scale press to study a drug product's tabletability and strain rate sensitivity, including collecting data on how the formulation behaves in relation to variations in compression force and dwell time. These factors affect the final thickness, density, and hardness (tensile strength) of the tablet and help determine the ideal compression profile. Mechanical and operational differences between an R&D press and a production press mean that transferring a product to full-scale production is not always successful.
Another critical factor to consider during scale-up from an R&D press to a large manufacturing press is compaction dwell time—the time (expressed in milliseconds) during which punches achieve maximum penetration in the die under the main compression rollers and are no longer moving vertically. Dwell time is a contributing factor to tablet strength and hardness. Because of differences in turret speed between an R&D press and a production press, the dwell time you had on your R&D press can be difficult to replicate on a production press.