title: Pharmaceutical properties of two ethenzamide-gentisic acid cocrystal polymorphs: Drug release profiles, spectroscopic studies and theoretical calculations.
abstract: The aim of this study was to evaluate the stability and solubility of the polymorphic forms of the ethenzamide (ET) - gentisic acid (GA) cocrystals during standard technological processes leading to tablet formation, such as compression and excipient addition. In this work two polymorphic forms of pharmaceutical cocrystals (ETGA) were characterized by13C and15N solid-state nuclear magnetic resonance and Fourier transformed infrared spectroscopy. Spectroscopic studies were supported by gauge including projector augmented wave (GIPAW) calculations of chemical shielding constants.Polymorphs of cocrystals were easily identified and characterized on the basis of solid-state spectroscopic studies. ETGA cocrystals behaviour during direct compressionand tabletting with excipient addition were tested. In order to choose the best tablet composition with suitable properties for the pharmaceutical industry dissolution profile studies of tablets containing polymorphic forms of cocrystals with selected excipients were carried out.
authors.affiliation: Faculty of Pharmacy with Laboratory Medicine Division, Medical University of Warsaw, Department of Inorganic and Analytical Chemistry, Banacha 1, 02-093, Warsaw, Poland. Electronic address: agnieszka.sokal@wu.edu.pl.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Sokal
authors.affiliation: Faculty of Pharmacy with Laboratory Medicine Division, Medical University of Warsaw, Department of Inorganic and Analytical Chemistry, Banacha 1, 02-093, Warsaw, Poland. Electronic address: edyta.pindelska@wum.edu.pl.
authors.forename: Edyta
authors.initials: E
authors.lastname: Pindelska
authors.affiliation: Faculty of Pharmacy with Laboratory Medicine Division, Medical University of Warsaw, Department of Physical Chemistry, Banacha 1, 02-093, Warsaw, Poland. Electronic address: lukasz.szeleszczuk@wum.edu.pl.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Szeleszczuk
authors.affiliation: Faculty of Pharmacy with Laboratory Medicine Division, Medical University of Warsaw, Department of Inorganic and Analytical Chemistry, Banacha 1, 02-093, Warsaw, Poland. Electronic address: waclaw.kolodziejski@wum.edu.pl.
authors.forename: Waclaw
authors.initials: W
authors.lastname: Kolodziejski
mesh_terms: D002626:Chemistry, Pharmaceutical; D003460:Crystallization; D003692:Delayed-Action Preparations; D004339:Drug Compounding; D065546:Drug Liberation; D004355:Drug Stability; D005841:Gentisates / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D012457:Salicylamides / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013607:Tablets
chemical_list: D003692:Delayed-Action Preparations; D005841:Gentisates; D012457:Salicylamides; D013607:Tablets; C018935:ethenzamide; C010925:2,5-dihydroxybenzoic acid
keywords: Cocrystals; Ethenzamide; Polymorphs; Solubility; Stability studies; ssNMR