title: Geometry of modified release formulations during dissolution--influence on performance of dosage forms with diclofenac sodium.
abstract: The objectives of the work included: presentation of magnetic resonance imaging (MRI) and fractal analysis based approach to comparison of dosage forms of different composition, structure, and assessment of the influence of the compositional factors i.e., matrix type, excipients etc., on properties and performance of the dosage form during drug dissolution. The work presents the first attempt to compare MRI data obtained for tablet formulations of different composition and characterized by distinct differences in hydration and drug dissolution mechanisms. The main difficulty, in such a case stems from differences in hydration behavior and tablet's geometry i.e., swelling, cracking, capping etc. A novel approach to characterization of matrix systems i.e., quantification of changes of geometrical complexity of the matrix shape during drug dissolution has been developed. Using three chosen commercial modified release tablet formulations with diclofenac sodium we present the method of parameterization of their geometrical complexity on the base of fractal analysis. The main result of the study is the correlation between the hydrating tablet behavior and drug dissolution - the increase of geometrical complexity expressed as fractal dimension relates to the increased variability of drug dissolution results.
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, Pharmaceutical Faculty, Jagiellonian University, ul. Medyczna 9, Kraków 30-688, Poland. Electronic address: mfdorozy@cyf-kr.edu.pl.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Dorożyński
authors.affiliation: Department of Magnetic Resonance Imaging, Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, Kraków 31-342, Poland; Institute of Technology, The Pedagogical University of Cracow, ul. Podchorążych 2, Kraków 30-084, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kulinowski
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, Pharmaceutical Faculty, Jagiellonian University, ul. Medyczna 9, Kraków 30-688, Poland.
authors.forename: Witold
authors.initials: W
authors.lastname: Jamróz
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, Pharmaceutical Faculty, Jagiellonian University, ul. Medyczna 9, Kraków 30-688, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Juszczyk
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D003692:Delayed-Action Preparations; D004008:Diclofenac / Q000008:administration & dosage* / Q000737:chemistry; D005079:Excipients / Q000737:chemistry*; D017709:Fractals; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012995:Solubility; D013607:Tablets
chemical_list: D003692:Delayed-Action Preparations; D005079:Excipients; D013607:Tablets; D004008:Diclofenac
keywords: Diclofenac sodium; Fractal dimension; MRI; Magnetic resonance imaging; Modified release