G. Srinivas, S.D. Dietz, S.C. Gebhard, M.V. Mundschau
TDA Research, Inc.,
Keywords: sorbents, graphene layers, toxic metals removal, ligand modified carbon
Summary:TDA Research, Inc. has scientifically designed and developed mesoporous, carbon sorbents to remove toxic metals from pharmaceutical mixtures and specifically palladium and other platinum-group elements used in catalysts for drug synthesis, while simultaneously minimizing the uptake of active pharmaceutical ingredients (API). New regulations in the U.S. and Europe require that Pd and Pt in the final API be limited to < 5 ppmw in oral medications and to 1000 m2·g-1) to aid chemisorption of metal species with ligands that can be displaced by nitrogen, phosphorus or optionally sulfur) species on the carbons. Nitrogen incorporated into carbonaceous edge sites forms highly basic pyridinic, pyridonic and pyrrolic species that strongly chelate complexes of platinum-group metals, while less strongly adsorbing the alkaloidal pharmaceutical agents that are typically also rich in basic nitrogen. Phosphorus-rich starting materials are also incorporated and are typically converted into metaphosphates and polyphosphates. Phosphates are partially reduced into phosphonates (phosphorus bound directly to carbon) that also strongly bind platinum group metals. The functional groups mimic those in DNA.