title: Parelectric spectroscopy of drug-carrier-systems--distribution of carrier masses or activation energies.
abstract: The answer of a high-frequency electromagnetic wave to a sample as termination of an open-ended coaxial line gives the mobility and the density of permanent electric dipole moments in the substance under test. As long as these dipoles are attached to carrier molecules of well defined masses, both parameters can be extracted from the reflected wave in a quick manner giving unambiguous results. The corresponding algorithm has been applied to solid lipid nanoparticles with glucocorticoid molecules attached to or incorporated in the carrier molecules. The results from measurements in the frequency region (0.1-100) MHz have recently been published. As soon as we have to envisage a distribution in carrier masses and/or in activation energies of the attached molecules, we have to apply a more sophisticated evaluation algorithm. The need for a more generalised algorithm is clear as well, when we have to deal with more than one dipole-carrying constituent in the samples. All these evaluation algorithms shall be presented together with the mathematical basis in a short but exact form.
authors.affiliation: Department of Physics, Freie Universität Berlin, Germany. krishnan@physik-hu.berlin.de
authors.forename: R
authors.initials: R
authors.lastname: Sivaramakrishnan
authors.forename: L
authors.initials: L
authors.lastname: Kankate
authors.forename: H
authors.initials: H
authors.lastname: Niehus
authors.forename: K D
authors.initials: KD
authors.lastname: Kramer
mesh_terms: D004337:Drug Carriers / Q000737:chemistry*; D008956:Models, Chemical; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D004337:Drug Carriers