title: Effect of fluidisation activity on end-point detection of a fluid bed drying process.
abstract: The influence of inlet air humidity variations on fluid bed drying end-point detection was the primary focus here. Various drying end-point criteria based on temperature and humidity measurements were compared. Seasonally changing inlet air humidity affects the moisture content of the finished granules, as long as the drying process remains unchanged. However, a specific moisture content of the finished granules is commonly desired after fluid bed drying. When experimental batches of varying inlet air humidity were compared at the beginning of the drying phase, the temperature of the granules increased linearly as the humidity of the inlet air increased. This effect causes variation in moisture contents of the final granules of different batches when the fixed temperature of the mass is used as an end-point criterion. With varying inlet air humidity, the often used DeltaT temperature difference method resulted in more precise estimation of the drying end-point than the constant temperature criterion. In this study new insights were found into the correlation between moisture content and temperature of the fluidising mass. Fluidisation activity greatly affected detection of drying end-point. Use of the DeltaT criterion requires proper fluidisation throughout the process.
authors.affiliation: Orion Corporation Orion Pharma, Orionintie 1, P.O. Box 65, FIN-02101 Espoo, Finland. tanja.lipsanen@orionpharma.com
authors.forename: Tanja
authors.initials: T
authors.lastname: Lipsanen
authors.forename: Osmo
authors.initials: O
authors.lastname: Antikainen
authors.forename: Heikki
authors.initials: H
authors.lastname: Räikkönen
authors.forename: Sari
authors.initials: S
authors.lastname: Airaksinen
authors.forename: Jouko
authors.initials: J
authors.lastname: Yliruusi
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003890:Desiccation / Q000379:methods*; D004339:Drug Compounding / Q000379:methods*; D005079:Excipients / Q000737:chemistry; D006813:Humidity; D007052:Ibuprofen / Q000008:administration & dosage / Q000737:chemistry; D007202:Indicators and Reagents; D007785:Lactose / Q000737:chemistry; D011205:Povidone / Q000737:chemistry; D011208:Powders; D013696:Temperature
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D005079:Excipients; D007202:Indicators and Reagents; D011208:Powders; D011205:Povidone; D007785:Lactose; D007052:Ibuprofen