title: A study of tablet dissolution by magnetic resonance electric current density imaging.
abstract: The electric current density imaging technique (CDI) was used to monitor the dissolution of ion releasing tablets (made of various carboxylic acids and of sodium chloride) by following conductivity changes in an agar-agar gel surrounding the tablet. Conductivity changes in the sample were used to calculate spatial and temporal changes of ionic concentrations in the sample. The experimental data for ion migration were compared to a mathematical model based on a solution of the diffusion equation with moving boundary conditions for the tablet geometry. Diffusion constants for different acids were determined by fitting the model to the experimental data. The experiments with dissolving tablets were used to demonstrate the potential of the CDI technique for measurement of ion concentration in the vicinity of ion releasing samples.
authors.affiliation: Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia. urska.mikac@ijs.si
authors.forename: Ursa
authors.initials: U
authors.lastname: Mikac
authors.forename: Alojz
authors.initials: A
authors.lastname: Demsar
authors.forename: Franci
authors.initials: F
authors.lastname: Demsar
authors.forename: Igor
authors.initials: I
authors.lastname: Sersa
mesh_terms: D003198:Computer Simulation; D004553:Electric Conductivity; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008422:Materials Testing / Q000379:methods*; D008956:Models, Chemical; D012995:Solubility; D013607:Tablets / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D013607:Tablets