title: Design and characterization of a new miniaturized rotating disk equipment for in vitro dissolution rate studies.
abstract: A miniaturized apparatus for the determination of the apparent in vitro dissolution rate has been designed, constructed and characterized. The miniaturized apparatus was based on a low volume dissolution cell and a disk in a rotating magnetic bar. The disk tablet is pressed directly into the bar with a press designed and constructed for this purpose. It requires approximately 5 mg of substance. The disk was positioned eccentrically on the bar with an external flow of medium to increase the rate of solvent flow over the disk surface. Six different drug substances were used. The dissolution media were sodium phosphate buffer, pH 7.0, and ammonium acetate buffer, pH 6.8. All quantifications were made by integrating the dissolution cell with high-performance liquid chromatography (HPLC) using diode-array detection (DAD). The obtained results were compared with data from a conventional rotating disk equipment, where the disk was centrically mounted. The dissolution rates at 100 rpm seemed to be on an average of 2-3 times higher for the miniaturized apparatus (RSD 0.2-56%). The preliminary studies of this prototype indicate that the miniaturized rotating disk is a promising design for the qualitative estimation of dissolution rates of substances, for example during screening in early drug discovery.
authors.affiliation: Division of Analytical Pharmaceutical Chemistry, Uppsala University, BMC, Box 574, SE-751 23 Uppsala, Sweden.
authors.forename: Anita M
authors.initials: AM
authors.lastname: Persson
authors.forename: Kajsa
authors.initials: K
authors.lastname: Baumann
authors.forename: Lars-Olof
authors.initials: LO
authors.lastname: Sundelöf
authors.forename: Walter
authors.initials: W
authors.lastname: Lindberg
authors.forename: Anders
authors.initials: A
authors.lastname: Sokolowski
authors.forename: Curt
authors.initials: C
authors.lastname: Pettersson
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007660:Ketoprofen / Q000737:chemistry; D007700:Kinetics; D008904:Miniaturization; D009288:Naproxen / Q000737:chemistry; D012995:Solubility
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D009288:Naproxen; D007660:Ketoprofen