title: Particular film formation of phenytoin at silica surfaces.
abstract: Given the increasing number of poorly soluble and thus poorly bioavailable active pharmaceutical materials, there is a demand for innovative formulation platforms for such molecules. Thus a focus on enhancing dissolution properties of poorly soluble drugs exists. Within this study, the spin coating of acetone solutions containing 5,5-diphenyl-2,4-imidazolidinedione (phenytoin) in various concentrations is evaluated. The results reveal strong variations of the morphology of deposited phenytoin crystals at silica surfaces. Individual separated particles are obtained on low phenytoin concentrations, and closely packed particular films form when the concentration is increased. As the material is isomorphic, these various morphologies have the same crystalline structure. Dissolution experiments reveal that both the apparent maximum solubility and as the dissolution rate are strongly enhanced compared to bulk powder, suggesting that formulation based on this preparative technique will allow overcoming the low solubility problematic for a variety of drugs.
authors.affiliation: Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology, University of Graz , 8010 Graz, Austria.
authors.forename: Oliver
authors.initials: O
authors.lastname: Werzer
authors.forename: Ramona
authors.initials: R
authors.lastname: Baumgartner
authors.forename: Michael
authors.initials: M
authors.lastname: Zawodzki
authors.forename: Eva
authors.initials: E
authors.lastname: Roblegg
mesh_terms: D002626:Chemistry, Pharmaceutical; D018625:Microscopy, Atomic Force; D010316:Particle Size; D010672:Phenytoin / Q000737:chemistry*; D011208:Powders; D012822:Silicon Dioxide / Q000737:chemistry*; D012995:Solubility
chemical_list: D011208:Powders; D010672:Phenytoin; D012822:Silicon Dioxide