title: The influence of residual water on the solid-state properties of freeze-dried fibrinogen.
abstract: The purpose of this work was to investigate the influence of residual water in freeze-dried protein powders on the dissolution behavior of the solid-state proteins. To that end, six freeze-dried fibrinogen powder lots were stored at four levels of relative humidity and analyzed with regard to the particle size and shape, the specific surface area, the solid state of protein and the inner surface. Furthermore, the dissolution behavior of the powders was investigated. We clearly identified differences in the specific surface area, specific inner surface area, crystallinity, particle size and shape, which we were able to correlate to the dissolution behavior. These differences were triggered due to the different levels of residual moisture during two weeks of storage. Thus, we were able to show that the storage conditions have significant impact on the processing of pharmaceutical protein materials.
authors.affiliation: Research Center Pharmaceutical Engineering, Graz, Austria; Institute for Process and Particle Engineering, University of Technology, Graz, Austria.
authors.forename: Verena
authors.initials: V
authors.lastname: Wahl
authors.affiliation: Research Center Pharmaceutical Engineering, Graz, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Leitgeb
authors.affiliation: Research Center Pharmaceutical Engineering, Graz, Austria; Bruker AXS GmbH, Graz, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Laggner
authors.affiliation: Baxter AG, Vienna, Austria.
authors.forename: Harald
authors.initials: H
authors.lastname: Pichler
authors.affiliation: Baxter AG, Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Liebminger
authors.affiliation: Research Center Pharmaceutical Engineering, Graz, Austria; Institute for Process and Particle Engineering, University of Technology, Graz, Austria. Electronic address: khinast@tugraz.at.
authors.forename: Johannes
authors.initials: J
authors.lastname: Khinast
mesh_terms: D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical; D003029:Coagulants / Q000737:chemistry*; D065546:Drug Liberation; D004355:Drug Stability; D004356:Drug Storage; D005340:Fibrinogen / Q000737:chemistry*; D005612:Freeze Drying; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011208:Powders; D055550:Protein Stability; D013499:Surface Properties; D014867:Water / Q000032:analysis*
chemical_list: D003029:Coagulants; D011208:Powders; D014867:Water; D005340:Fibrinogen
keywords: BET surface; Crystallinity; Dissolution; Inner surface; Particle shape; Particle size; Solid state protein