title: Drug-polymer intermolecular interactions in hot-melt extruded solid dispersions.
abstract: The purpose of the study was to investigate and identify the interactions within solid dispersions of cationic drugs and anionic polymers processed by hot-melt extrusion (HME) technique. Propranolol HCl (PRP) and diphenhydramine HCl (DPD) were used as model cationic active substances while pH sensitive anionic methacrylic acid based methyl methacrylate copolymers Eudragit L100 (L100) and ethyl acrylate copolymer Eudragit L100-55 (Acryl EZE) (L100-55) were used as polymeric carriers. The extrudates were further characterised using various physicochemical characterisation techniques to determine the morphology, the drug state within the polymer matrices and the type of drug-polymer interactions. Molecular modelling predicted the existence of two possible H-bonding types while the X-ray photon spectroscopy (XPS) advanced surface analysis of the extrudates revealed intermolecular ionic interactions between the API amino functional groups and the polymer carboxylic groups through the formation of hydrogen bonding. The magnitude of the intermolecular interactions varied according to the drug-polymer miscibility.
authors.affiliation: School of Science, University of Greenwich, Central Avenue, Chatham Maritime, Chatham, Kent ME4 4TB, United Kingdom.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Maniruzzaman
authors.forename: David J
authors.initials: DJ
authors.lastname: Morgan
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Mendham
authors.forename: Jiayun
authors.initials: J
authors.lastname: Pang
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Snowden
authors.forename: Dennis
authors.initials: D
authors.lastname: Douroumis
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000838:Anions; D002152:Calorimetry, Differential Scanning; D002412:Cations; D004155:Diphenhydramine / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding / Q000379:methods; D006358:Hot Temperature; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D056951:Photoelectron Spectroscopy; D011109:Polymethacrylic Acids / Q000737:chemistry*; D011433:Propranolol / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D044366:Transition Temperature; D014961:X-Ray Diffraction
chemical_list: D000180:Acrylic Resins; D000838:Anions; D002412:Cations; D004337:Drug Carriers; C446821:Eudragit L100-55; D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer; D004155:Diphenhydramine; D011433:Propranolol