title: Impact of drying on solid state modifications and drug distribution in ibuprofen-loaded calcium stearate pellets.
abstract: Drying is a common pharmaceutical process, whose potential to alter the final drug properties-even at relatively low temperatures-is often neglected. The present study addresses the impact of drying at 20 and 50 °C on wet-extruded calcium stearate (CaSt) pellets. Drying at 20 °C caused the majority of ibuprofen to accumulate at the pellet surface due to a strong convective flow from the pellet's center to the surface. In contrast, pellets dried at 50 °C still contained ibuprofen in the pellet's interior due to the higher drying rate and the associated film breakage during drying. Moreover, the higher drying temperature caused CaSt to form a second lamellar phase and ibuprofen to convert (partly) into its amorphous state. Overall, the drying process affected the solid state and the spatial ibuprofen distribution within the pellet. Knowledge of these effects can aid in tailoring advanced multipellet formulations.
authors.affiliation: Institute for Process and Particle Engineering, Graz University of Technology , Inffeldgasse 13/3, 8010 Graz, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Schrank
authors.forename: B
authors.initials: B
authors.lastname: Kann
authors.forename: E
authors.initials: E
authors.lastname: Saurugger
authors.forename: H
authors.initials: H
authors.lastname: Ehmann
authors.forename: O
authors.initials: O
authors.lastname: Werzer
authors.forename: M
authors.initials: M
authors.lastname: Windbergs
authors.forename: B J
authors.initials: BJ
authors.lastname: Glasser
authors.forename: A
authors.initials: A
authors.lastname: Zimmer
authors.forename: J
authors.initials: J
authors.lastname: Khinast
authors.forename: E
authors.initials: E
authors.lastname: Roblegg
mesh_terms: D002118:Calcium / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D003080:Cold Temperature; D003890:Desiccation; D007052:Ibuprofen / Q000737:chemistry* / Q000378:metabolism*; D013059:Spectrum Analysis, Raman; D013228:Stearates / Q000737:chemistry*
chemical_list: D013228:Stearates; D002118:Calcium; D007052:Ibuprofen