title: Improving flow properties of ibuprofen by fluidized bed particle thin-coating.
abstract: The surfaces of ibuprofen particles (d(50) 42 microm) were modified by coating the particles with diluted aqueous hydroxypropyl methylcellulose (HPMC) solution in an instrumentated top-spray fluid bed granulator. The objective was to evaluate whether an extremely thin polymer coating could be an alternative to granulation in enhancing powder flow and processing properties. The studied variables were inlet air temperature and spray rate. The treated powders showed a clear improvement in flow rate as measured with a flow meter designed for powders with poor flow properties. The particle size was determined using optical microscopy and image analysis. The particle size, size distribution and circularity of the treated and untreated ibuprofen batches showed no difference from each other. Consequently, the improvement in flow properties can be attributed to the trace amounts of hydroxypropyl methylcellulose applied onto the particle surfaces. In conclusion, fluidized bed particle thin-coating (PTC) alters the surface of ibuprofen powder particles and improves the flow properties of ibuprofen powder with changes in neither particle size, size distribution nor morphology.
authors.affiliation: Division of Pharmaceutical Technology, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5 E), University of Helsinki, Helsinki FI-00014, Finland. henrik.ehlers@helsinki.fi
authors.forename: Henrik
authors.initials: H
authors.lastname: Ehlers
authors.forename: Heikki
authors.initials: H
authors.lastname: Räikkönen
authors.forename: Osmo
authors.initials: O
authors.lastname: Antikainen
authors.forename: Jyrki
authors.initials: J
authors.lastname: Heinämäki
authors.forename: Jouko
authors.initials: J
authors.lastname: Yliruusi
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004339:Drug Compounding / Q000379:methods*; D065347:Hypromellose Derivatives; D007052:Ibuprofen / Q000737:chemistry*; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011208:Powders; D012995:Solubility; D012996:Solutions; D013499:Surface Properties; D013696:Temperature
chemical_list: D011208:Powders; D012996:Solutions; D065347:Hypromellose Derivatives; D008747:Methylcellulose; D007052:Ibuprofen