title: Sedimentation and resuspendability evaluation of pharmaceutical suspensions by low-field one dimensional pulsed field gradient NMR profilometry.
abstract: In order to study the sedimentation of pharmaceutical suspensions using low-field one dimensional pulsed field gradient nuclear magnetic resonance (1D pfg NMR) profilometry, the accuracy of signal acquisition as well as the spatial resolution of a commercial spectrometer operating at 23.4 MHz was investigated. The use of a solid Teflon spacer revealed that the accuracy of signal acquisition was independent of spatial position (height). The standard deviation of distance determinations was less than 150 µm, whereas the accuracy of water content determination was within 2% in the central part of the detection zone and deteriorated to 4% in the outer parts. The study of aqueous paramagnetic MnCl2 solutions indicated an exponential relationship between the relative signal intensity and the transverse relaxation decay constant. From this relationship, the relative water content of suspensions could be derived from their signal intensity relative to that of water. Using concentrated paliperidone palmitate dispersions as model suspensions, low-field 1D pfg NMR profilometry has been proven to be suitable for the evaluation of both the sedimentation and resuspendability behavior of viscous, opaque suspensions, for which visual detection of homogeneity may be difficult.
authors.affiliation: Particle and Interfacial Technology Group, Ghent University, Gent, Belgium.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Wuxin
authors.forename: José
authors.initials: J
authors.lastname: Martins
authors.forename: Pieter
authors.initials: P
authors.lastname: Saveyn
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Govoreanu
authors.forename: Katrien
authors.initials: K
authors.lastname: Verbruggen
authors.forename: Tina
authors.initials: T
authors.lastname: Ariën
authors.forename: Arne
authors.initials: A
authors.lastname: Verliefde
authors.forename: Paul
authors.initials: P
authors.lastname: Van der Meeren
mesh_terms: D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D007555:Isoxazoles / Q000008:administration & dosage / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D017895:Manganese Compounds / Q000737:chemistry; D000068882:Paliperidone Palmitate; D010168:Palmitates / Q000008:administration & dosage / Q000737:chemistry*; D013535:Suspensions; D014867:Water / Q000737:chemistry
chemical_list: D014150:Antipsychotic Agents; D002712:Chlorides; D007555:Isoxazoles; D017895:Manganese Compounds; D010168:Palmitates; D013535:Suspensions; D014867:Water; C025340:manganese chloride; D000068882:Paliperidone Palmitate