title: An electrical impedance tomography-based approach to monitor in vitro sodium chloride dissolution from pharmaceutical tablets.
abstract: An approach to monitor in vitro dissolution process from pharmaceutical tablets utilizing electrical impedance tomography (EIT) is introduced. In the demonstration, a tablet containing sodium chloride (NaCl) was dissolution tested using tap water as a dissolution medium within an apparatus similar to the United States Pharmacopoeia dissolution apparatus II. During the process, the three-dimensional sodium chloride concentration distribution was monitored with EIT measurements as a function of time. For EIT measurements, an array of electrodes was attached on the boundary of the dissolution vessel, a set of alternating electric currents was injected through the electrodes, and the resulting voltages were measured. With these data and by applying mathematical algorithms, an approximation for the spatial/temporal concentration distribution inside the vessel was computed. It was found that the computed distributions were relatively homogeneous. A NaCl release curve was computed by integrating the concentration distribution over the vessel volume, and the final value of the curve matched well with the reference point based on the weight loss of the tablet. Finally, EIT monitoring is suggested to be used for research and product development purposes.
authors.affiliation: Department of Physics, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland. ville.rimpilainen@uku.fi
authors.forename: Ville
authors.initials: V
authors.lastname: Rimpiläinen
authors.forename: Lasse M
authors.initials: LM
authors.lastname: Heikkinen
authors.forename: Marko
authors.initials: M
authors.lastname: Kuosmanen
authors.forename: Anssi
authors.initials: A
authors.lastname: Lehikoinen
authors.forename: Arto
authors.initials: A
authors.lastname: Voutilainen
authors.forename: Marko
authors.initials: M
authors.lastname: Vauhkonen
authors.forename: Jarkko
authors.initials: J
authors.lastname: Ketolainen
mesh_terms: D055808:Drug Discovery; D017097:Electric Impedance; D012965:Sodium Chloride / Q000737:chemistry*; D012996:Solutions; D013607:Tablets; D014054:Tomography / Q000295:instrumentation / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D013607:Tablets; D014867:Water; D012965:Sodium Chloride