title: Novel oral phosphate binder with nanocrystalline maghemite-phosphate binding capacity and pH effect.
abstract: Hyperphosphatemia is one of the main risk factors contributing to morbidity and mortality in patients with end stage renal disease. The demand for a new phosphate binder is continuously increasing since the number of patients suffering under hyperphosphatemia is growing. However, side effects and high pill burden of currently available phosphate binders are the main reasons for low compliance and uncontrolled serum phosphate levels. Therefore, the aim of this study was to develop a novel phosphate binder with a high phosphate binding capacity over the entire gastrointestinal (GI) pH range. This novel phosphate binder C-PAM-10 is based on d-mannose coated nanocrystalline maghemite and belongs to the new class of phosphate binders, called the "iron based agents". It was possible to obtain a phosphate binding product that showed very high phosphate binding capacities with the characteristic of being pH independent at relevant pH ranges. The simulation of a GI passage ranging from pH 1.2 to pH 7.5 showed a 2.5 times higher phosphate binding capacity compared to the commonly used phosphate binder sevelamer carbonate. The simulation of a pH sensitive coating that releases the iron based phosphate binder at pH values ≥4.5 still showed a very high phosphate binding capacity combined with very low iron release which might decrease iron related side effects in vivo. Therefore, C-PAM-10 and its variations may be very promising candidates as a superior phosphate binder.
authors.affiliation: Charité - Universitätsmedizin Berlin, Department of Radiology, Charitéplatz 1, 10117 Berlin, Germany; Freie Universität Berlin, Department of Pharmaceutics, Biopharmaceutics & NutriCosmetics, Kelchstr. 31, 12169 Berlin, Germany.
authors.forename: T M-H
authors.initials: TM
authors.lastname: Nguyen
authors.affiliation: Freie Universität Berlin, Department of Pharmaceutics, Biopharmaceutics & NutriCosmetics, Kelchstr. 31, 12169 Berlin, Germany.
authors.forename: R H
authors.initials: RH
authors.lastname: Müller
authors.affiliation: Charité - Universitätsmedizin Berlin, Department of Radiology, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Taupitz
authors.affiliation: Charité - Universitätsmedizin Berlin, Department of Radiology, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schnorr
authors.affiliation: Charité - Universitätsmedizin Berlin, Department of Radiology, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Hamm
authors.affiliation: Charité - Universitätsmedizin Berlin, Department of Radiology, Charitéplatz 1, 10117 Berlin, Germany. Electronic address: susanne.wagner@charite.de.
authors.forename: S
authors.initials: S
authors.lastname: Wagner
mesh_terms: D000284:Administration, Oral; D002614:Chelating Agents / Q000138:chemical synthesis* / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D041981:Gastrointestinal Tract / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D008358:Mannose / Q000737:chemistry; D008954:Models, Biological; D053758:Nanoparticles / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D000069603:Sevelamer / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D005290:Ferric Compounds; D010710:Phosphates; C000499:ferric oxide; D000069603:Sevelamer; D007501:Iron; D008358:Mannose
keywords: Iron release; Maghemite; Nanocrystals; Phosphate binder; pH effect