title: Molecular-level characterization of probucol nanocrystal in water by in situ solid-state NMR spectroscopy.
abstract: The molecular state of colloidal probucol nanoparticles with additives was evaluated by (13)C in situ solid-state NMR spectroscopy. The nanoparticles were obtained by dispersing a ternary co-ground mixture of probucol/polyvinylpyrrolidon (PVP)/sodium dodecyl sulfate (SDS) in water. Their mean particle size was found to be approximately 150 nm by dynamic light scattering and cryogenic-scanning electron microscopy measurements. The results of the (13)C in situ solid-state NMR spectroscopy showed that probucol existed in the crystalline state (form I) in water. (13)C liquid-state NMR results indicated that PVP and SDS interacted with probucol in water. Their broad signals suggested that the surface interaction of the probucol nanocrystal with PVP and SDS stabilized the suspension. In addition, a freeze-dried sample of the suspension was studied by (13)C solid-state NMR and powder X-ray diffraction experiments, which confirmed the presence of the probucol nanocrystals. The combination of the in situ solid-state, solid-state, and liquid-state NMR measurement results provided molecular-level insights about the role of intermolecular interactions in the design of nanoformulations.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8675, Japan.
authors.forename: Junying
authors.initials: J
authors.lastname: Zhang
authors.forename: Kenjirou
authors.initials: K
authors.lastname: Higashi
authors.forename: Waree
authors.initials: W
authors.lastname: Limwikrant
authors.forename: Kunikazu
authors.initials: K
authors.lastname: Moribe
authors.forename: Keiji
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D002247:Carbon Isotopes; D002626:Chemistry, Pharmaceutical; D003102:Colloids; D020285:Cryoelectron Microscopy; D003460:Crystallization; D018360:Crystallography, X-Ray; D005612:Freeze Drying; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D036103:Nanotechnology; D010316:Particle Size; D011205:Povidone / Q000737:chemistry; D033362:Powder Diffraction; D011341:Probucol / Q000737:chemistry*; D012542:Scattering, Radiation; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D003102:Colloids; D013501:Surface-Active Agents; D014867:Water; D012967:Sodium Dodecyl Sulfate; D011205:Povidone; D011341:Probucol