title: Effects of drying technique on extrusion-spheronisation granules and tablet properties.
abstract: Extrusion-spheronisation was used to generate smooth, highly spherical granules of a microcrystalline cellulose/propyl gallate/water paste. Freeze-drying retained the shape and size of the granules, whereas oven-drying produced roughened granules due to the uneven shrinkage of the wet powders. Compaction of one size fraction indicated that the granule strength differed noticeably, with the oven-dried samples producing tablets of lower voidage for a given applied compaction pressure. There was a reasonable correlation between tablet crushing strength and voidage. Major differences were observed in tablet dissolution, with the freeze-dried material exhibiting a two-regime behaviour and an initial dissolution rate constant an order of magnitude greater than the oven-dried form. Both the voidage and dissolution characteristics are postulated to be determined by the microstructure established during drying.
authors.affiliation: University of Cambridge, Department of Chemical Engineering, New Museums Site, Pembroke Street, Cambridge CB2 3RA, UK.
authors.forename: B
authors.initials: B
authors.lastname: Song
authors.forename: S L
authors.initials: SL
authors.lastname: Rough
authors.forename: D I
authors.initials: DI
authors.lastname: Wilson
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D019245:Compressive Strength; D003692:Delayed-Action Preparations; D003890:Desiccation; D005079:Excipients / Q000737:chemistry*; D005612:Freeze Drying; D007700:Kinetics; D008954:Models, Biological; D010316:Particle Size; D016062:Porosity; D011208:Powders; D011435:Propyl Gallate / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D013607:Tablets; D013678:Technology, Pharmaceutical / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D000975:Antioxidants; D003692:Delayed-Action Preparations; D005079:Excipients; D011208:Powders; D013607:Tablets; D014867:Water; D011435:Propyl Gallate; D002482:Cellulose; C109691:microcrystalline cellulose